1. Two-way Tables
BPS chapter 6
© 2006 W.H. Freeman and Company

2. Summarizing data
To summarize data on the closing stock prices of AT&T and Sprint for 90 days, you should use
a scatterplot.
a two-way table.
none of the above.

3. Summarizing data (answer)
To summarize data on the closing stock prices of AT&T and Sprint for 90 days, you should use
a scatterplot.
a two-way table.
none of the above.

4. Summarizing data
To summarize data on whether subjects received a flu vaccine and whether they developed the flu during one winter season, you should use
a scatterplot.
a two-way table.
none of the above.

5. Summarizing data (answer)
To summarize data on whether subjects received a flu vaccine and whether they developed the flu during one winter season, you should use
a scatterplot.
a two-way table.
none of the above.

6. Summarizing data
To summarize data on gender and heart rates (number of beats per minute), you should use
a scatterplot.
a two-way table.
none of the above.

7. Summarizing data (answer)
To summarize data on gender and heart rates (number of beats per minute), you should use
a scatterplot.
a two-way table.
none of the above.

8. Two-way tables
The following two-way table summarizes the number of cancer patients treated at two cancer clinics who died or survived. What percentage of the cancer patients survived?
390 / 1000 = 39%
320 / 1000 = 32%
710 / 1000 = 71%
290 / 1000 = 29%

9. Two-way tables (answer)
The following two-way table summarizes the number of cancer patients treated at two cancer clinics who died or survived. What percentage of the cancer patients survived?
390 / 1000 = 39%
320 / 1000 = 32%
710 / 1000 = 71%
290 / 1000 = 29%

10. Two-way tables
The following two-way table summarizes the number of cancer patients treated at two cancer clinics who died or survived. What percentage of the cancer patients at Clinic A survived?
390 / 1000 = 39%
390 / 710 = 55%
710 / 1000 = 71%
390 / 600 = 65%

11. Two-way tables (answer)
The following two-way table summarizes the number of cancer patients treated at two cancer clinics who died or survived. What percentage of the cancer patients at Clinic A survived?
390 / 1000 = 39%
390 / 710 = 55%
710 / 1000 = 71%
390 / 600 = 65%

12. Two-way tables
The following two-way table summarizes the number of cancer patients treated at two cancer clinics who died or survived. What percentage of the cancer patients who survived were treated at Clinic B?
320 / 1000 = 32%
320 / 400 = 80%
320 / 710 = 45%
710 / 1000 = 71%

13. Two-way tables (answer)
The following two-way table summarizes the number of cancer patients treated at two cancer clinics who died or survived. What percentage of the cancer patients who survived were treated at Clinic B?
320 / 1000 = 32%
320 / 400 = 80%
320 / 710 = 45%
710 / 1000 = 71%

14. Two-way tables
The following two-way table summarizes the number of single and married students in a basic statistics course who like watching professional football. The percentage of students in this class who are married is considered
A marginal percentage
A conditional percentage
Something else

15. Two-way tables (answer)
The following two-way table summarizes the number of single and married students in a basic statistics course who like watching professional football. The percentage of students in this class who are married is considered
A marginal percentage
A conditional percentage
Something else

16. Two-way tables
The following two-way table summarizes the number of single and married students in a basic statistics course who like watching professional football. The percentage of married students in this class who like football is considered
A marginal percentage
A conditional percentage
Something else

17. Two-way tables (answer)
The following two-way table summarizes the number of single and married students in a basic statistics course who like watching professional football. The percentage of married students in this class who like football is considered
A marginal percentage
A conditional percentage
Something else

18. Two-way tables
The following two-way table summarizes the number of single and married students in a basic statistics course who like watching professional football. The percentage students who are married and do not like football is considered
A marginal percentage
A conditional percentage
Something else

19. Two-way tables (answer)
The following two-way table summarizes the number of single and married students in a basic statistics course who like watching professional football. The percentage students who are married and do not like football is considered
A marginal percentage
A conditional percentage
Something else

20. Association
A study was conducted to determine whether the amount of time students spend practicing concepts on the computer is associated with their math score on the Iowa Test of Basic Skills (ITBS). Computer time and ITBS math score was recorded on students at three schools.
Results
Overall, the association between computer time and math score was negative.
Within each school, the association between computer time and math score was positive.
Given the results of this study, what can you conclude?
The association between computer time and math score is the result of a cause and effect relationship.
Variables with a strong curved relationship can have a correlation of zero.
Simpson’s paradox is present.

21. Association (answer)
A study was conducted to determine whether the amount of time students spend practicing concepts on the computer is associated with their math score on the Iowa Test of Basic Skills (ITBS). Computer time and ITBS math score was recorded on students at three schools.
Results
Overall, the association between computer time and math score was negative.
Within each school, the association between computer time and math score was positive.
Given the results of this study, what can you conclude?
The association between computer time and math score is the result of a cause and effect relationship.
Variables with a strong curved relationship can have a correlation of zero.
Simpson’s paradox is present.

22. Simpson’s paradox
Do the following show Simpson’s paradox?
Yes.
No.

23. Simpson’s paradox (answer)
Do the following show Simpson’s paradox?
Yes.
No.