- kradermath

Transcription

- kradermath

Final Exam
Practice Questions
MAT 141 – Statistics
These practice questions accompany Sullivan, Fundamentals of Statistics, 4th edition.
These questions are provided to help you prepare for the final exam. However, please note the
following:
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


These practice questions cover only a sample of the material that we covered in this course.
You are responsible for all of the material covered in the course, whether or not the material
is included in this set of practice questions.
The practice questions emphasize certain topics more than others. Do not assume that the
final exam will emphasize the same topics.
You will have 1 hr. 45 min. to complete the final exam. This set of practice questions is about
twice as long as the final exam.
While I hope you find these practice questions helpful, it should be just one of several tools
you use to help you prepare for the final exam. Other suggestions include:
― Begin studying as early as possible. Don’t try to cram an entire semester’s worth of
material the night before the exam.
― Review previous exams and homework assignments and make sure you can rework
problems that were not correct the first time.
― Use the chapter Study Guides as a checklist of topics that were covered in this
course.
― Work extra problems, especially in areas where you have had difficulty.
― Make sure you understand concepts as well as procedures, i.e., you should
understand not only how to do something but why you are doing it. Find a study
partner and drill each other on concepts (which are listed in the study guides). If
you have difficulty explaining something, you probably need to study it some more.
― If you have questions, please take advantage of your instructor’s office hours and/or
the tutoring available in the Individual Learning Center.
Read the following and then answer Questions 1 – 3:
On the first day of class, an instructor asks his students to supply the following information about
themselves:
― Height (in inches)
― Time they woke up that morning
― Number of siblings who live in their household
― Place of birth
1. Which variable can be classified as a “quantitative discrete” variable?
(A) Height
(B) Wake-up time
(C) Number of siblings in household
(D) Place of birth
(E) None of these
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Final Exam Practice Questions
G. H. Krader, Instructor
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2. Which variable can be classified as a “qualitative” variable?
(A) Height
(B) Wake-up time
(D) Place of birth
(E) None of these
3. If the instructor made a list of all the heights, the numbers in that list would be a:
(A) Population
(B) Sample
(C) Variable
(D) Data set
(E) None of these
4. Which variable has a “nominal” level of measurement?
(A) Height
(B) Wake-up time
(D) Place of birth
(E) None of these
5. Which variable has an “ordinal” level of measurement?
(A) Height
(B) Wake-up time
(D) Place of birth
(E) None of these
6. Which variable has an “interval” level of measurement?
(A) Height
(B) Wake-up time
(D) Place of birth
(E) None of these
7. A study on attitudes about smoking is conducted at a college. All students are divided by class
(freshman, sophomore, junior, and senior). Then a simple random sample is selected from each
class and interviewed. Which sampling technique was used in the study?
(A) Random
(C) Systematic
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(B) Stratified
(D) Cluster
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8. In a statistical study of a new drug, data are collected from two groups of people – those who
received the new drug and those who received a pill with no active ingredients. The people who
received the pill with no active ingredients are called:
(A) Experimental (or treatment) group
(B) Observational group
(C) Control group
(D) Placebo
9. A health club surveyed 40 randomly selected members and found that the mean weight of those
surveyed is 157 pounds. “157 pounds” is an example of a:
(A) Sample
(C) Parameter
(B) Statistic
(D) Variable
10. In the previous question, the 40 people who were surveyed are a:
(A) Sample
(C) Control group
(B) Population
(D) Treatment group
11. At Widget Manufacturing, the mean salary of all female workers is $35,000 and the mean salary
of all male workers is $41,000. Which of the following is true about the mean salary of all
workers (male and female combined) at the company?
(A) It must be $38,000.
(B) It must be larger than the median salary.
(C) It must be between $35,000 and $41,000.
(D) All of the above.
12. Which of the following measures roughly describes the average location of data points relative to
the mean?
(A)
(B)
(C)
(D)
Median
Percentile
Standard deviation
Mode
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Percent
13. An industrial company researches the mean pH
level of the water in a nearby river. For fifty
randomly selected water samples the pH level
was recorded. The distribution of recorded pH
levels was presented in the following relative
frequency distribution histogram. Which of the
following is appropriate conclusion?
35
25
20
15
10
5
pH levels
0
5.875
6.125
6.375
6.625
6.875
7.125
7.375
7.625
Number of guests
(A) [100,110)
(B) [110,120)
(C) [130,140)
(D) [150,160)
40
30
(A) Approximately 86% of the analyzed water
samples have pH levels between 6.375 and
7.125.
(B) About 5% of the water samples have pH
levels below 6.1.
(C) The pH levels are uniformly distributed.
(D) All of the above
(E) None of these
14. Fifty hotel guests were asked how much money
they paid for their hotel room last night. The
results are shown in the histogram at the right.
Which class contains the 80th percentile?
45
100
110
120
130
140
150
160
170
180
190
200
Price of hotel room (dollars)
The numbers on the horizontal axis represent lower
class limits, e.g., the first class is [100,110), the second
class is [110,120), etc.
15. Another name for “Q1” is:
(A) 1st percentile
(B) 10th percentile
(C) 25th percentile
(D) Median
(E) None of these
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16. A study was performed to analyze the time (in minutes)
it takes students to complete an exam. A study was done
on 50 randomly selected students. The distribution of
times (in minutes) was presented in the following boxplot. Which of the following is an appropriate
conclusion?
(A) More than half of the students took longer than 40
minutes to complete a test.
(B) The mean time to complete a test was longer than
40 minutes.
(C) The distribution is skewed-left.
(E) None of these
17. The manufacturer wants to compare the
calling range (in miles) of its 900-MHz
cordless telephone to the calling range of its
leading competitor. A comparative study was
done using two independent samples of 50
telephones from the manufacturer and its
competitor. The distributions of the calling
ranges from the manufacturer and its leading
competitor are presented in the graph. Which
of the following is an appropriate conclusion?
0
50
100
time
competitor
manufacturer
1200
1250
1300
(A) Both distributions are symmetric.
calling range (miles)
(B) The calling range is longer on average for
the manufacturer’s 900-MHz cordless
telephones.
(C) The amount of variation is approximately the same for both the manufacturer and its leading
competitor.
(E) None of these
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18. In which of the following distributions is the mean greater than the median?
(A)
(B)
(C)
(D) Distributions B and C
(E) The mean and the median are
equal in all three distributions.
19. The pie-chart displays the distribution of the NASA space shuttle operation expenditures (in
millions of dollars) for 2001. What is the appropriate conclusion?
NASA space shuttle operations
Expenditures in 2001
Main Engine (9.8%)
Mission/launch
operations (29.2%)
External Tank ( 13.1%)
Solid rocket booster
(5.1%)
Orbiter and integration
( 27.1%)
Reusable solid rocket
motor ( 15.7%)
(A) More than 50% of the budget was spent on mission/launch operations together with orbiter
and integration.
(B) The smallest percent of the budget was spend on solid rocket booster.
(C) Approximately the same amount of money was spent on the external tank and reusable solid
rocket motor.
(E) None of these
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20. The “z-score” associated with a data point measures
(A) The frequency of the data point
(B) How far the data point is from the mean
(C) A probability
(D) The spread of the distribution
(E) None of these
21. After grading a Statistics test in a class of 25 students, the instructor calculated the mean, median
and standard deviation of the test scores. The student with the highest score found a grading
error, which changed her score from 96 to 98. Which of the measures is not impacted by this
change?
(A) Mean
(B) Median
(C) Standard deviation
(D) All three measures are impacted by the change
(E) None of the measures is impacted by the change
22. Which of the following pairs of events are disjoint (mutually exclusive)?
(A) A single die is rolled once.
Event A: “The result is an odd number”
Event B: “The result is a 3”
(B) A student is randomly selected.
Event A: “The student is taking a mathematics course”
Event B: “The student is taking a business course”
(C) A single card is drawn from a deck of 52 cards.
Event A: “The result is a club”
Event B: “The result is a King”
(D) A single die is rolled.
Event A: “The result is a number greater than 4”
Event B: “The result is a number less than 4”
(E) None of these
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Use the following table to answer Questions 23 – 26:
A blood bank catalogs the types of blood, including positive or negative Rh-factor, given by donors
during the last five days. The number of donors who gave each blood is listed in the table below.
Rh-factor
Rh-positive
Rh -negative
Totals
O
150
30
180
Blood Type
A
B
135
37
25
12
160
49
Totals
AB
13
8
21
335
75
410
23. Find the probability that a randomly selected donor does not have blood type A.
(A) 0.3902
(B) 0.6098
(C) 0.3293
(D) 0.0610
24. Find the probability that a randomly selected donor has either blood type AB or Rh-positive
factor.
(A) 0.8683
(B) 0.9
(C) 0.8366
(D) 0.1317
25. Find the probability that a randomly selected donor has blood type B.
(A) 0.7551
(B) 0.8805
(C) 0.0902
(D) 0.1195
26. Find the probability that a randomly selected donor has blood type B and Rh-negative factor?
(A) 0.2449
(B) 0.16
(C) 0.2732
(D) 0.0293
27. Which of the following variables is a discrete random variable?
(A) The number of siblings of a randomly selected student.
(B) The number of people (crew size) on a randomly selected mission by NASA.
(C) The number of tellers available to serve customers in a bank between 12 and 1 pm.
(E) None of these
28. Which of the following variables is a continuous random variable?
(A) The amount of milk in a “1-gallon” carton
(B) The amount of sugar (in pounds) eaten each day in the US.
(C) The daily temperature of a patient during a hospital stay
(E) None of these
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Use the following probability distribution to answer Questions 29 – 31
The table shows the probabilities of prior DWI (Driving While Intoxicated) sentences for jail inmates
convicted of DWI. (Source: US Department of Justice)
Number of prior DWI sentences
Probability
0
0.512
1
0.301
2
0.132
3
0.055
29. What is the probability of selecting a jail inmate with at least 2 prior DWI sentences?
(A) 0.055
(B) 0.187
(C) 0.945
(D) 0.813
30. What is the probability of selecting a jail inmate with at most 1 prior DWI sentences?
(A) 0.488
(B) 0.187
(C) 0.945
(D) 0.813
31. What is the expected number of prior DWI sentences for a randomly selected jail inmate?
(A) Between 0 and 1
(C) Between 2 and 3
(B) Between 1 and 2
(D) Between 3 and 4
32. You roll two dice – a red die and a green die. What is the probability of getting doubles (both
dice land on the same number)?
(A) 1/3
(B) 1/6
(C) 1/18
(D) 1/36
33. Rolling the same two dice, what is the probability of the following event: red die lands on an odd
number and green die lands on 5 or 6
(A) 1/3
(B) 1/6
(C) 4/6
(D) 5/6
34. An airline reports that 20% of its passengers on international flights order special meals. If four
international passengers are selected at random, what is the probability that all four passengers
ordered a special meal?
(A) 0.8
(B) 0.2
(C) 0.05
(D) 0.0016
35. A PIN (personal identification number) is a sequence of any four characters from the 26 letters of
the alphabet and the digits 0-9, with repetitions allowed. How many such PINs are possible?
(A) 1,679,616
(B) 1,413,720
(C) 260
(D) 456,976
36. Continuing with the previous question, how many PINs would be possible if repetitions were not
allowed?
(A) 1,413,720
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(B) 358,800
(C) 234
(D) 58,905
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37. Which of the following are true about counting methods?
(A) In a combination order does not matter, but different orders result in different
permutations.
(B) In a permutation, repetition is not allowed, but in a combination repetition is allowed.
(C) For groups of r objects chosen from a group of n objects, there are more permutations than
there are combinations.
(D) Both A and C
(E) Both B and C
38. A community college offers 15 different math courses. A researcher wants to mail a survey to
students in three of the courses. How many different ways can the three courses be selected?
(A) 5
(B) 455
(C) 2730
(D) 3375
39. Valley View Hospital allows its patients to choose from a menu of 3 breakfast entrees, 5 lunch
entrees and 8 dinner entrees. How many daily menu choices are there?
(A) 16
(B) 560
(C) 3360
(D) 120
40. Which of the following variables is a binomial random variable?
(A) A fair coin is tossed until it lands on heads 10 times.
X = the total number of tosses.
(B) A fair die is rolled 10 times.
X = the number of times the die landed on a “3”.
(C) A box contains 3 blue marbles, 2 red, and 5 white marbles. Three marbles from the box are
selected at random, without replacement.
X= the number of red marbles out of the 3 marbles.
(E) None of these.
41. According to the Daily Racing Form, the probability is about 67% that the favorite in a horse race
will finish in the money (first, second, or third place). In the next eight races, what is the
probability that the favorite finishes in the money in exactly two races?
(A) 0.0162
(B) 0.0003
(C) 0.9997
(D) 0.9838
42. In a recent referendum, 30% of the voters supported a property tax increase to provide
additional money for education. If 5 voters are chosen at random, what is the probability that at
least one of the voters supported the property tax increase?
(A) 0.36
(B) 0.47
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(C) 0.53
(D) 0.83
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43. In the year 2000, the periodical Zero Population Growth reported that the US led the fully
industrialized world in teen pregnancy rates, with 40% of US females getting pregnant at least
once before reaching the age of 20. In a sample of 10 randomly selected 20-year-old females,
what is the probability that at least 6 of them have been pregnant at least once before the age of
20?
(A) 0.1115
(B) 0.8338
(C) 0.1662
(D) 0.9452
44. As reported by Television Bureau of Advertising, Inc., in Trends in Television, 84.2% of US
households have a VCR. If 18 households are randomly selected for observational study, what is
the probability that at most 15 households will have a VCR?
(A) 0.5581
(B) 0.4419
(C) 0.244
(D) 0.8019
45. Nine percent of men cannot distinguish between the colors red and green. This is the type of
color blindness that causes problems with traffic signals. If six unrelated men are randomly
selected for a study of traffic signal perception, what is the probability that more than 3 of them
have difficulty distinguishing between red and green?
(A) 0.0110
(B) 0.9992
(C) 0.0008
(D) 0.0118
46. In a housing study, it was found that 26% of college students live in campus housing (based on
data from the Independent Insurance Agents of America). In a sample of 25 randomly selected
college students, how many students do you expect will be living in campus housing?
(A) Between 2 and 3
(C) Between 6 and 7
(B) Between 4 and 5
(D) Between 18 and 19
47. In a normal distribution, approximately 99.7% of the data points lie within how many standard
deviations of the mean?
(A) 1 standard deviation
(C) 3 standard deviations
(B) 2 standard deviations
(D) 4 standard deviations
48. The diagram at the right shows three normal
distributions. Which of the distributions has the
greatest standard deviation?
(A)
(B)
(C)
(D)
A
Distribution A
Distribution B
Distribution C
All three distributions have the same standard
deviation
B
C
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49. An airline knows from experience that the number of suitcases that are lost each week on a
certain route is normally distributed with the mean of 15.5 suitcases and a standard deviation of
3.6 suitcases. What is the probability that during a given week the airline will lose between 10
and 20 suitcases on that route?
(A) 0.8314
(B) 0.3944
(C) 0.1056
(D) 0.4040
50. Assume that the lengths of pregnancies are normally distributed with a mean of 268 days and a
standard deviation of 15 days. What is the probability of a pregnancy lasting at least 300 days?
(A) 0.0166
(B) 0.9834
(C) 0.2375
(D) 0.3189
51. Assume that the starting salaries of elementary school teachers in the US are normally
distributed with a mean of $31,000 and a standard deviation of $3,000. What percent of US
elementary school teachers receive a starting salary of at most $25,000?
(A) 2.28%
(B) 99.81%
(C) 21.13%
(D) 98.27%
52. The average price of a certain type of used car is $6500 with a standard deviation of $850. If a
used car dealer wants to deal with the middle 75% of the market, what will the dealer’s price
range be?
(A) $6229 – $6771
(D) $5522 – $7478
(B) $6423 – $6577
(C) $5926 – $7073
53. The total cholesterol of US women ages 50-59 is approximately normally distributed with a
mean of 228 milligrams per deciliter of blood and a standard deviation of 43.8 milligrams per
deciliter of blood. What is the total cholesterol level exceeded by only 2.5% of women ages 5059?
(A) 313.85
(B) 142.15
(C) 155.95
(D) 300.05
54. On a dry surface, the braking distance (in meters) of a Pontiac Grand AM SE can be approximated
by a normal distribution with a mean of 45.1 meters and standard deviation of 0.5 meters. What
braking distance of a Pontiac Grand AM SE represents the first quartile?
(A) 44.98
(B) 44.76
(C) 45.44
(D) 45.23
55. The distribution of actual weights of 8-oz chocolate bars produced by a certain machine is
normal with a mean of 8.1 ounces and standard deviation of 0.1 ounces. What is the probability
that the mean of 9 such chocolate bars will be less than 8.15 ounces?
(A) 0.0668
(B) 0.9332
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(C) 0.6915
(D) 0.3085
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56. In a large population of adults, IQ scores are normally distributed with a mean of 112 and
standard deviation of 20. What is the probability that the mean IQ of 16 adults will be between
105 and 123?
(A) 0.9053
(B) 0.3456
(C) 0.0669
(D) 0.8159
57. An automobile insurer has found that repair claims have a mean of $920 and a standard
deviation of $870. What is the probability that the mean of 100 claims is larger than $1,000?
(A) 0.9200
(B) 0.8212
(C) 0.0800
(D) 0.1788
58. If the heights of US adult women are normally distributed with a mean of 65.5 inches, then which
of the following is least likely to occur?
(A) The height of a randomly selected woman is more than 72 inches.
(B) The mean height from a random sample of 10 women is more than 72 inches.
(C) The mean height from a random sample of 40 women is more than 72 inches.
(D) All three events are equally likely.
59. Which of the following is true about the standard normal distribution?
(A) It is bell-shaped and symmetric around the mean
(B) The mean, median, and mode are equal.
(C) The area underneath the total curve is 1.
(E) None of these
60. Which of the following is true about a Student’s t-distribution?
(A) It is a bell-shaped and symmetric distribution around the mean.
(B) There are infinitely many t-distributions.
(C) There is more variation in a t-distribution than in the standard normal distribution.
(E) None of these
61. Which of the following is true about confidence interval estimates?
(A) The higher the confidence level, the larger the margin of error.
(B) The larger the sample size, the smaller the margin of error.
(C) The higher the confidence level, the wider the confidence interval estimate.
(E) None of these
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62. Nielsen Media Research wants to estimate the mean amount of time (in minutes) that full-time
college students spend watching television each weekday. Find the minimum sample size
required to estimate that mean within 15 minutes with 95% confidence. From a pilot study the
standard deviation is estimated to be 112.2 minutes.
(A) 15
(B) 215
(C) 152
(D) 110
63. A pollster reports that 32% of US voters approve of the president’s job performance “plus or
minus 4%.” In this poll, “4%” is called the:
(A) Confidence level
(C) Significance level
(B) Margin of error
(D) Standard deviation
64. A study was conducted to estimate hospital costs for accident victims who wore seat belts. The
distribution of hospital costs is approximately normal. Sixteen randomly selected cases have
been selected for a study, and the mean hospital cost for the sample of 16 cases was $9000 with a
standard deviation of $2000. Construct a 99% confidence interval estimate for the mean
hospital cost for all accident victims who wore seat belts.
(A) ($7720, $10,280)
(C) ($7526.60, $10,473.00)
(B) ($7539.50, $10,460.50)
(D) ($8020, $9980)
65. A sociologist wants to determine the current percentage of US households using e-mail.
Determine the minimum sample size required in order to be 95% confident that her estimate is
within 4% of the true proportion of all US households using e-mail. Suppose a pilot study
indicated that 65% of surveyed households use e-mail.
(A) 547
(B) 115
(C) 423
(D) 601
66. In a Gallup poll, 1025 randomly selected adults were surveyed, and 298 of them said that they
used the Internet for shopping at least a few times a year. Find a 95% confidence interval
estimate of the proportion of adults who use the Internet for shopping at least a few times a year.
(A) (26.01%, 32.13%)
(C) (23.51%, 34.63%)
(B) (26.29%, 31.85%)
(D) (17.95%, 40.19%)
67. In a hypothesis test, which of the following is true about the p-value?
(A) Assuming the null hypothesis is true, the p-value is the probability of obtaining a sample
statistic with a value as extreme or more extreme than the one determined from the sampled
data.
(B) The p-value is the maximum allowed probability of rejecting the null hypothesis when it is
true.
(C) The larger the p-value, the more evidence you have to reject the null hypothesis.
(E) None of these.
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68. Which of the following is true about hypothesis testing?
(A) The alternative hypothesis is always a statement of inequality.
(B) The null hypothesis is always a statement of equality.
(C) Both hypotheses are stated in terms of a population parameter.
(E) None of these.
69. In a random sample of 100 American males between the ages of 18 and 21 the average height
was 6.1 ft with a standard deviation of 0.21 ft. Specify the hypotheses used to test the claim that
the mean height of American males between 18 and 21 years of age is now over 6 ft.
(A) H0: μ=6
H1: μ≠6
(B) H0: μ=6
(C) H0: μ=6
H1: μ>6
(D) H0: μ=6.1
H1: μ<6
H1: μ>6.1
70. The state police commander reported that 35% of drivers on a busy freeway are driving at least
10 mph over the speed limit. In a sample of 120 cars, a highway patrol officer with a radar gun
found 48 drivers (i.e., 40%) who exceeded the speed limit by 10 mph or more. The patrol officer
claims that the police commander is not correct. State the hypotheses used to test the patrol
officer’s claim.
(A) H0: p=0.40
H1: p≠0.40
(B) H0: μ=10
(C) H0: p=0.35
H1: p>0.35
(D) H0: p=0.35
H1: μ<10
H1: p0.35
71. A simple random sample of 25 postal service employees found that the average time these
employees had worked for the postal service was 7 years with a standard deviation of 2 years.
The distribution of the time the population of employees have worked for the postal service is
approximately normal. Find the p-value used to determine whether there is enough evidence to
support the claim that the average time an employee worked for the postal service has decreased
from 7.5 years (which was the average about 10 years ago)?
(A) 0.11
(B) 0.22
(C) 0.44
(D) 0.76
72. An auto repair shop reports that 75% of its jobs are completed ahead of schedule. An audit of
104 jobs found that 73 were completed ahead of schedule. Find the p-value used to test the
claim that fewer than 75% of jobs were completed ahead of schedule.
(A) 0.13
(B) 0.26
(C) 0.74
(D) 1.13
73. In a hypothesis test, there is still a possibility that the null hypothesis is true even if it is rejected
The probability of rejecting the null hypothesis when it is true is called the:
(A)
(B)
(C)
(D)
p-value
z-value
Significance level (α)
Margin of error
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74. According to corporate headquarters, customers at Hempel’s Department Store have a mean
household income of $91,600. The manager of the store in Northwoods Mall claims that her
customers have higher incomes. She surveys 100 randomly selected customers and finds that
their mean income is $96,321. She uses that statistic along with the sample standard deviation
to compute a p-value and test her claim. If p-value < α, how should she state the results?
(A) There is enough evidence to support the store manager’s claim that the mean household
income of Northwoods Mall customers is greater than $91,600.
(B) There is not enough evidence to support the store manager’s claim that the mean household
income of Northwoods Mall customers is greater than $91,600.
(C) There is enough evidence to support corporate headquarters’ claim that the mean household
income of Hempel’s customers is $91,600.
(D) There is enough evidence to support the store manager’s claim that the mean household
income of Northwoods Mall customers is $96,321.
75. The American Automobile Association (AAA) claims that 54% of fatal car/truck accidents are
caused by driver error. A researcher studied 30 randomly selected accidents and found that 14
were caused by driver error, which leads the researcher to dispute the AAA’s claim. The
researcher performs a hypothesis test. If p-value > α, how should the researcher summarize her
results?
(A) There is enough evidence to dispute the AAA’s claim that 54% of fatal car/truck accidents
are caused by driver error.
(B) There is not enough evidence to dispute the AAA’s claim that 54% of fatal/car truck
accidents are caused by driver error.
(C) There is enough evidence to support the AAA’s claim that 54% of fatal car/truck accidents
are caused by driver error.
(D) There is not enough evidence to support the AAA’s claim that 54% of fatal car/truck
accidents are caused by driver error.
76. Newton Center and Newton Junction are two adjacent towns with very similar demographics.
For years, Newton Realty had told its clients that real estate prices in the two towns were the
same. However, a real estate agent at a competing firm sampled the price of real estate in each
town and got the following results:
Newton Center
Newton Junction
n1 = 35
n 2 = 40
X 1 = $63,255
s1 = $5602
X 2 = $59,102
s 2 = $4731
The competing agent used this data to test Newton Realty’s claim. If p-value < α, how should the
competing agent summarize her results?
(A) There is enough evidence to support the claim that the mean price in Newton Center is
higher than the mean price in Newton Junction.
(B) There is enough evidence to support the claim that the mean price in Newton Center is the
same as the mean price in Newton Junction.
(C) There is enough evidence to support the claim that the mean price in Newton Center is
different than the mean price in Newton Junction.
(D) There is enough evidence to support the claim that the difference between the mean prices
is $4153.
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77. Increasing numbers of businesses are offering child-care to their employees. In fact, a local
Chamber of Commerce says that 40% of its members offer child care. However, in a sample of 50
businesses, you find only 15 who offered child care. At α=0.05, test the claim that the actual
number of businesses offering child care is less than 40%. What is the appropriate conclusion?
(A) Reject the null hypothesis. There is not enough evidence to support the claim that less than
40% of businesses offer child care.
(B) Reject the null hypothesis. There is enough evidence to support the claim that less than 40%
of businesses offer child care.
(C) Do not reject the null hypothesis. There is enough evidence to support the claim that 40% of
businesses offer child care.
(D) Do not reject the null hypothesis. There is not enough evidence to support the claim that
less than 40% of businesses offer child care.
78. A researcher wants to test the effect of a calcium supplement on the taste of yogurt. The taste
was measured on the scales 1 to 10, 1 being “very unpleasant” and 10 being “very pleasant”. A
mean rating for 16 randomly selected adults who tasted yogurt containing the extra calcium was
6.5 with a standard deviation of 1.5. An independent random sample of 14 adults who tasted
yogurt without the added calcium gave a mean rating of 7 with a standard deviation of 2. The
distribution of ratings for taste with and without the added calcium are approximately normally
distributed. At the 10% significance level, do the data provide sufficient evidence to support the
claim that the mean rating of the taste is significantly lower for the yogurt with the added
calcium? What is the appropriate p-value?
p  value  0.01
(C) 0.05  p  value  0.1
(E) p  value  0.25
(A)
0.01  p  value  0.05
(D) 0.1  p  value  0.25
(B)
79. Is the mean weight of regular Coke less than the mean weight of regular Pepsi? To test this
claim, two independent samples of cans of each brand were selected for testing. The sample
statistics are summarized in a table below. The distributions of weights of regular Coke and
regular Pepsi are approximately normal. At the 5% significance level, what is the appropriate
conclusion?
Regular Coke
Regular Pepsi
n1 = 15
x1 = 0.8168
s1 = 0.0075
n 2 = 10
x 2 = 0.8241
s 2 = 0.0057
(A) Reject the null hypothesis. Data do not support the claim that the mean weight of regular
Coke is less than the mean weight of regular Pepsi.
(B) Reject the null hypothesis. Data support the claim that the mean weight of regular Coke is
less than the mean weight of regular Pepsi.
(C) Do not reject the null hypothesis. Data do not support the claim that the mean weight of
regular Coke is less than the mean weight of regular Pepsi.
(D) Do not reject the null hypothesis. Data support the claim that the mean weight of regular
Coke is less than the mean weight of regular Pepsi.
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80. Which of the following situations describe two dependent samples.
(A) A teacher compares the pre-test and post-test scores of the same set of students.
(B) A teacher compares the scores of students using a computer-based method of instruction
with the scores of other students using a traditional method of instruction.
(C) A teacher compares the scores of students in her class on a standardized test with the
national average score.
(E) None of these
3300
Acres harvested
81. The scatter plot represents the relationship
between the number of acres of rice planted
(in thousands) and number of acres of rice
harvested (in thousands) in the United States
for eight years. Which of the following is an
appropriate conclusion?
3200
3100
3000
2900
(A) The linear correlation coefficient is closer
to 1 than to 0.
2800
(B) There is very strong positive linear
relationship between the number of acres
2800
2900
3000
3100
3200
of rice planted and the number of acres of
Acres planted
rice harvested.
(C) As the number of acres of rice planted
increases, the number of acres of rice harvested tends to increase as well.
(E) None of these
3300
82. In a linear regression analysis, a correlation coefficient of 0.9 with a high level of significance
would mean:
(A)
(B)
(C)
(D)
(E)
There is a strong linear correlation between the two variables.
There is little or no correlation between the two variables.
As the independent variable decreases, the dependent variable also tends to decrease.
Both A and C.
None of these
83. A linear regression analysis has shown that there is a strong positive linear correlation between
the amount of sugar consumed and the total number of childhood cavities. Which of the
following can not be said based on this regression analysis alone?
(A)
(B)
(C)
(D)
(E)
The correlation coefficient is close to 1.
As sugar consumption increases, so does the number of cavities.
Increased sugar consumption causes cavities.
Sugar consumption can be used to predict the number of cavities.
None of these (i.e., all four statements are true).
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Page 19
84. Which of the following sampling methods does not require a list of individuals in the population?
(A)
(B)
(C)
(D)
Simple random sampling
Systematic sampling
Stratified sampling
Cluster sampling
85. A drug company wanted to test a new depression medication. The researchers found 600 adults
aged 25-35 and randomly assigned them to two groups. The first group received the new drug,
while the second received a placebo. After one month of treatment, the percentage of each group
whose depression symptoms decreased was recorded and compared. What is the response
variable in this experiment?
(A)
(B)
(C)
(D)
The percentage of participants with decreased depression symptoms
The type of drug (medication or placebo)
The ages of the adults who participated in the study
The treatment time (one month)
86. Identify the experimental units in the study described in the previous question.
(A)
(B)
(C)
(D)
The 600 adults who participated in the study
The amount of drug (or placebo) that each adult received.
The percentage of participants with decreased depression symptoms
The ages of the adults who participated in the study
87. Between 1996 and 2006, the percentage of students who graduated from an adult education
program rose steadily from 83.2% to 84.1%. A time-series graph is drawn to depict the results.
Which of the following techniques will exaggerate the improvement in graduation rate?
(A)
(B)
(C)
(D)
Use lots of different colors in the graph.
Do not label the years on the x-axis.
Truncate the y-axis.
All of the above.
88. An administrative assistant orders four types of pens from an office supply company. 20% of
the pens cost $1.29 each, 10% of the pens cost $1.69 each, 25% of the pens cost $1.79 each and
45% of the pens cost $0.99 each. Determine the mean cost per pen.
(A) $0.33
(B) $1.32
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(C) $1.44
(D) $1.49
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Page 20
89. A random sample of sale prices of homes yielded the following summary information:
Q1: $81,000
Median: $138,000
Q3: $169,000
Which of the following sale prices would be considered outliers?
(A)
(B)
(C)
(D)
Any home that costs more than $169,000
90. If nothing is known about the shape of a distribution, what percentage of observations fall within
three standard deviations of the mean?
(A)
(B)
(C)
(D)
At least 89%
At most 11%
Approximately 95%
Approximately 99.7%
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Section Numbers
If you are stuck, review the appropriate section in the textbook before looking up the answer.
(Solutions are on the following page.)
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Sec.*
1.1
1.1
1.1
1.1
1.1
1.1
1.4
1.6
1.1
1.1
3.1
3.2
2.2
2.2, 3.4
3.4
3.5
3.5
3.1
2.1
3.4
3.1, 3.2
5.2
5.2
5.2
5.1
5.2
6.1
6.1
6.1
6.1
No.
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Sec.*
6.1
5.1, 5.3
5.3
5.3, 6.2
5.5
5.5
5.5
5.5
5.5
6.2
6.2
6.2
6.2
6.2
6.2
6.2
3.2
3.2, 7.1
7.2
7.2
7.2
7.2
7.2
7.2
8.1
8.1
8.1
8.1
7.2
9.2
No.
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
Sec.*
9.1
9.2
9.1
9.2
9.1
9.1
10.1
10.1
10.3
10.1
10.3
10.2
10.1
10.3
10.2
11.3
10.2
11.3
11.3
11.2
4.1
4.1
4.1
1.3, 1.4
1.6
1.6
2.3
3.3, 6.1
3.4
3.2
* Section numbers refer to: Sullivan, Fundamentals of Statistics, 4th edition.
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Page 22
Solutions
If you are stuck, review the appropriate section in the textbook before looking up the answer.
(Section numbers without solutions are on the previous page.)
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Sec.*
1.1
1.1
1.1
1.1
1.1
1.1
1.4
1.6
1.1
1.1
3.1
3.2
2.2
2.2, 3.4
3.4
3.5
3.5
3.1
2.1
3.4
3.1, 3.2
5.2
5.2
5.2
5.1
5.2
6.1
6.1
6.1
6.1
Ans.
C
D
D
D
E
B
B
C
B
A
C
C
A
C
C
B
D
B
D
B
B
D
B
C
D
D
D
D
B
D
No.
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Sec.*
6.1
5.1, 5.3
5.3
5.3, 6.2
5.5
5.5
5.5
5.5
5.5
6.2
6.2
6.2
6.2
6.2
6.2
6.2
3.2
3.2, 7.1
7.2
7.2
7.2
7.2
7.2
7.2
8.1
8.1
8.1
8.1
7.2
9.2
Ans.
A
B
B
D
A
A
D
B
D
B
A
D
C
A
C
C
C
C
A
A
A
D
A
B
B
A
D
C
D
D
No.
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
Sec.*
9.1
9.2
9.1
9.2
9.1
9.1
10.1
10.1
10.3
10.1
10.3
10.2
10.1
10.3
10.2
11.3
10.2
11.3
11.3
11.2
4.1
4.1
4.1
1.3, 1.4
1.6
1.6
2.3
3.3, 6.1
3.4
3.2
Ans.
D
B
B
C
A
B
A
D
C
D
A
A
A
A
B
C
D
D
B
A
D
A
C
B
A
A
C
B
D
A
* Section numbers refer to: Sullivan, Fundamentals of Statistics, 4th edition.
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Iss 5.0

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