2. 1
1
% 75 percent of teens age 12-17 use the
internet.
True
False
3. 2 People under 18 make up what percentage of the U.S. population?
A 10%
B 24.1%
C 29%
D 48%
4. 3 9% of the U.S. population speaks English as their first language.
True
False
5. 4 What percent of teens are either “indifferent,” “don't care,” or “care but
don't take an active role” in being concerned about the effects of man
on nature?
A 12.2%
B 50%
C 68.5%
D 95.3%
6. 5 Male high school students in the U.S. have higher SAT scores on
average than females.
True
False
8. CHECK FOR RECENT DATA
% 75 percent of teens age 12-17 use the internet.
True
False
1950 2000 2009
This statement was
true in the year 2000!
What are other examples of data that would go
out of date quickly?
9. USE GOOD COMPARISON DATA
7 People under 18 make up what percentage of the U.S. population?
A 10%
B 24.1%
C 29%
D 48%
10. The census is a sample of what
population?
http://www.census.gov/
11. CHECK THE SAMPLE
8 9% of the U.S. population speaks English as their first language.
Yes
No
9% of the world’s
population speaks
English!
http://news.nationalgeographic.com/news/2004/02/0226_040226_language.html
12. MAKE SURE IT’S A RANDOM SAMPLE
9
What percent of teens are either “indifferent,” “don't care,” or “care
but don't take an active role” in being concerned about the effects
of man on nature?
A 12.2%
B 50%
C 68.5%
D 95.3%
If this is a survey of teens that use the computer often, is there a chance this sample
would be less likely to play outside? Would this change their views on the
environment?
http://www.stageoflife.com/TeensandNature.aspx
13. Another example of a biased sample . . .
Percent of Kids in
Different Schools in
Champaign
Jefferson: 100%
Sample: 30 students at Jefferson Middle
School
Is this a random sample?
14. Percent of Kids in
Different Schools in
Champaign
Jefferson: 30%
Edison: 30%
Franklin: 30%
Sample: 300
Random: Yes
What kinds of places could you go to get a random
sample of middle school students?
15. BE CRITICAL
10
Male high school students in the U.S. have higher scores on
average than females.
True
False
http://www.britannica.com/blogs/2009/07/more-on-the-male-female-sat-math-test-gap/
16. In 2007 the SAT was taken by
798,030 females but only 690,500
males, a gap of more than
100,000 people. Assuming that
SAT takers represent the top
portion of the performance
distribution, this surplus of
females taking the SAT means
that the female group dips farther
down into the performance
distribution than does the male
group. It is therefore not surprising
that females, on average, score
somewhat lower than males. The
gender gap is likely in large part a
sampling artifact.
17. 20% of white youth . . . 50% of girls . . .
Who knows you best?
90% of youth test scores
60% of teens like rap music
