CH 24 WS

AP Statistics
CH 24 Classwork
Name_________________________________
Date______________
Period_______
1. Tees. Does it matter what kind of a tee a golfer places the ball on? The company that manufactures
“Stinger” tees claims that the thinner shaft and smaller head will lessen resistance and drag, reducing spin and
allowing the ball to travel farther. In August 2003, Golf Laboratories, Inc., compared the distance traveled by
golf balls hit off of regular wooden tees to those hit off of Stinger tees. All of the balls were struck by the same
golf club using a robotic device set to swing the club head at approximately 95 mph. Summary statistics from
the test are shown in the table. Assume that 6 balls were hit off of each tee and that the data were suitable for
inference.
Total
Distance
(yards)
Ball Velocity
(mph)
Club
Velocity
(mph)
Regular Tee
Avg.
SD
227.17
2.14
127.00
0.89
96.17
0.41
Stinger Tee
Avg.
SD
241.00
2.76
128.83
0.41
96.17
0.52
Is there evidence that the balls hit off the Stinger tees would have a higher initial velocity?
Given the test results on golf tees described above, is there evidence that balls hit off Stinger tees would travel
farther? Again assume that 6 balls were hit off each tee and that the data were suitable for inference.
2. Hurricanes. The data below show the number of hurricanes before and after 1970. Create an appropriate
visual display and determine whether these data are appropriate for testing whether or not there has been a
change in the frequency of hurricanes.
1944-1969: 3,2,1,2,4 3,7,2,3,3 2,5,2,2,4 2,2,6,0,2 5,1,3,1,0 3
1970-2000: 2,1,0,1,2 3,2,1,2,2 2,3,1,1,3 0,1,3,2,1 2,1,1,0,5 6,1,3,5,3
_______3. We wish to test if a new feed increases the mean weight gain compared to an old feed. At the
conclusion of the experiment it was found that the new feed gave a 10 kg bigger gain than the old feed. A twosample t-test with the proper one-sided alternative was done and the resulting p-value was .082. This means:
A) There is an 8.2% chance the null hypothesis is true.
B) There was only a 8.2% chance of observing an increase greater than 10 kg , assuming the null hypothesis was
true.
C) There was only an 8.2% chance of observing an increase greater than 10 kg, assuming the null hypothesis
was false.
D) There is an 8.2% chance the alternate hypothesis is true.
E) There is only an 8.2% chance of getting a 10 kg increase.
_______4. A researcher is going to conduct an experiment in order to compare two drugs – a new drug and an
old drug. The researcher would like to see whether there is sufficient evidence to say that the new drug is better
than the old drug. In this problem, the researcher will commit a type I error if:
A) She concludes that the drugs are equal in effectiveness when in fact the new drug is better.
B) She concludes that the drugs are equal in effectiveness when in fact the old drug is better.
C) She concludes that the old drug is better when in fact the new drug is better.
D) She concludes that the new drug is better when in fact the drugs are equal in effectiveness.
E) She concludes that the old drug is better when in fact the drugs are equal in effectiveness.