HW Jan 9-16 - WRDSB teachers
- Ja1.q 9+^ - 16**, zq t S
Data and graphs may be used to make convincing arguments.
Some arguments are more convincing than others.
For example, Lucas and Tia made 2 different arguments using the data in this table.
Amount of Time Spent with Friends after School (to nearest minute)
< 30 min
min 6(H9 min 90-l19min >120 min
Lucas added the data in columns 4 and 5 to find that 22 boys and 19 girls spent more
than 90 min with their friends after school. He used this to argue that boys spend
more time with their friends than girls do.
Tia added the totals of columns 3 and 4 to find that 63 boys and girls spend
60-120 min with their friends after school. She used this to argue that over 600/o of
boys and girls spend l-2h with their friends after school.
Tia's argument is more convincing than Lucas'because only 3 more boys than girls
spend more than 90 min with their friends after school. The numbers are too close
for Lucas'argument to be convincing.
Sometimes, a graph shows a trend or
relationship in the data. When you use data to
predict a value in the future, or to estimate a
value between given data, you make an
inference. When you use data to make
conclusion, you infer.
For exarnple, using the data from this graph,
you can make valid arguments and inferences.
Mark High School
Canned Food Drive
The graph shows that, other than 2003, the height of the bar for each year is higher
than the previous year. A convincing argument would be that St. Mark High School
is collecting more cans from year to year.
You can also infer that, if this trend continues, the number of cans collected in 2006
rvill be greater than the number collected in 2005. The prediction, or inference, you
can make is that over 50 000 cans will be collected in 2006.
2. Tawanda recorded in this table the type of cars driven by people in his neighbourhood.
Type of Car
He used the data in the table to make this argument:
"Most people in my neighbourhood drive A vcln."
Is Tawanda's argument valid? Explain.
Cornpone fhe nurnber
vons fo the totol
b) Write two convincing arguments that could be justified by the data in the table.
does this graph show?
Students Who Dressed Up
for Spirit Week
b) Below are 3 arguments made by members of the Student Council.
A: Boys have less school spirit than girls.
B: Grade 8 students have more school spirit than Grade 7 students.
C: Grade 7 students have more school spirit than Grade 8 students.
If there are about the same number of students in each grade, which argument do you
think is most valid? fustily your answer.
does the graph show?
Attendance at Movie Theatre
b) What inferences can you make from the graph? Explain.
bars for adults
How can the graph be used to justifr each argument?
is the most popular day for people to go to the movies.
heights of the
bars for adults
ii) Approximately equal numbers of adults and youths go the movies on
FridaS Saturday, and Sunday.
Add the heights
af the bars for
the 3 days for