Statistics Exam 30 questions
1. Say you’ve obtained a chisquare of 12.56. You have a chi square critical value of 3.481. Based on this information, what do you conclude?
A) Fail to reject the null hypothesis
B) Reject the Null Hypothesis
2. Say you’ve obtained a chisquare of 10.95. You have a chi square critical value of 9.210. Based on this information, what do you conclude?
A) Fail to reject the null hypothesis
B) Reject the Null Hypothesis
3. For the table below, what would be the chisquare critical value if you were doing a hypothesis test and your significance level was 0.01?
Counseling for Mental Problems 
Total 

Yes 
No 

Do you have Kids? 
Yes 
39 
695 
734 
No 
19 
256 
275 

Total 
58 
951 
1009 
D 9.210
4) For the table below, what is the expected frequency for Yes Demoted and Pretty Happy? (Remember that you don’t need to do all the expected frequencies to get just one…)
General Happiness 
Total 

Very Happy 
Pretty Happy 
Not Too Happy 

Were Demoted? 
Yes 
5 
12 
7 
24 
No 
294 
545 
99 
938 

Total 
299 
557 
106 
962 
5. For the table below, what is the expected frequency for No Kids and Yes Counseling for Mental Problems? (Remember that you don’t need to do all the expected frequencies to get just one…)
Counseling for Mental Problems 
Total 

Yes 
No 

Do you have Kids? 
Yes 
39 
695 
734 
No 
19 
256 
275 

Total 
58 
951 
1009 
6. For the table below, what is the expected frequency for No Demoted and Not too Happy? (Remember that you don’t need to do all the expected frequencies to get just one…)
General Happiness 
Total 

Very Happy 
Pretty Happy 
Not Too Happy 

Were Demoted? 
Yes 
5 
12 
7 
24 
No 
294 
545 
99 
938 

Total 
299 
557 
106 
962 
7. For the table below, what is the expected frequency for No Kids and No Counseling for Mental Problems? (Remember that you don’t need to do all the expected frequencies to get just one…)
Counseling for Mental Problems 
Total 

Yes 
No 

Do you have Kids? 
Yes 
39 
695 
734 
No 
19 
256 
275 

Total 
58 
951 
1009 
8. In the table below, what is the column marginal for “ever had home broken into = no”?
Ever had home broken into? 

Gender 
Yes 
No 
Total 
Female 
1558 
1064 
2622 
Male 
1567 
1069 
2636 
Total 
3125 
2133 
5258 
9. For the table below, what is the chisquare? (Remember, you can round to whole numbers for the expected frequency, but leave at least 2 decimal places on for all other chisquare calculations).
Counseling for Mental Problems 
Total 

Yes 
No 

Do you have Kids? 
Yes 
39 
695 
734 
No 
19 
256 
275 

Total 
58 
951 
1009 
10. For the table below, what is the chisquare? (Round this way or the answer will not turn out right: you can round to whole numbers for the expected frequency, but leave at least 2 decimal places on for all other chisquare calculations). Choose the answer that is closest.
General Happiness 
Total 

Very Happy 
Pretty Happy 
Not Too Happy 

Were Demoted? 
Yes 
5 
12 
7 
24 
No 
294 
545 
99 
938 

Total 
299 
557 
106 
962 
11. You’ve obtained a chi square of 34.56, and it’s significant. You want to test how strong the relationship between these two variables is. You have a sample size of 75. You have a table with 2 rows and 4 columns. What’s your Cramer’s V?
12. Say you have a phicoefficient of 0.51. How strong is the relationship between the two variables it tests?
13. You’ve obtained a chi square of 10.98, and it’s significant. You want to test how strong the relationship between these two variables is. You have a sample size of 50. What’s your phicoefficient?
14. You’ve obtained a chi square of 16.52, and it’s significant. You want to test how strong the relationship between these two variables is. You have a sample size of 75. What’s your phicoefficient?
15. Is the interpretation of the following regression line correct?
Regression line:
$\stackrel{}{}$y
⏜
=
20.5
+
1.4
(
x
)
Interpretation: For every one unit increase in y, there is a 1.4 increase in x.
16. Is the interpretation of the following regression line correct?
Regression line:
$\stackrel{}{}$y
⏜
=
0.89
+
2.3
(
x
)
Interpretation: For every one unit increase in y, there is a 0.89 increase in x.
17. Is the interpretation of the following regression line correct?
Regression line:
y
⏜
=
0.5
−
1.7
(
x
)
y
⏜
=
0.5
−
1.7
(
x
)
Interpretation: For every one unit increase in x, there is a 1.7 decrease in y.
18. What type of relationship, positive or negative, is portrayed in the following sentence? When crime worsens, individuals’ willingness to help their neighborhoods decreases.
19. What type of relationship, positive or negative, is portrayed in the following sentence? The statistical relationship shows that when foreclosure rates increase, crime worsens.
20. Find the correlation between the two following variables: % of people in neighborhood on welfare and the number of people who have police contact.
x  y 
40  9 
59  25 
20  3 
15  10 
21. What is the strength of the following correlation? 0.156
22. What is the strength of the following correlation? 0.451
23. A friend of yours suggests that at least 10% of people at your university have had something stolen from them on campus in the past year. This is your population value. You take a random sample of 100 people in you classes to determine if your friend is correct, you think that they may be wrong. You find that 15% of them have had something stolen.
Would you use z or t to test this hypothesis?
24. A friend of yours suggests that at least 10% of people at your university have had something stolen from them on campus in the past year. This is your population value. You take a random sample of 100 people in you classes to determine if your friend is correct, you think that they may be wrong. You find that 15% of them have had something stolen.
Would you have a one or two tailed test?
25. A friend of yours suggests that at least 10% of people at your university have had something stolen from them on campus in the past year. This is your population value. You take a random sample of 100 people in you classes to determine if your friend is correct. You find that 15% of them have had something stolen.
What is the value of your test statistic?
26. What are the age differences among teens that report being delinquent (or not)? Conduct a two mean hypothesis test to ascertain whether there is an age difference between teens who report being delinquent and teens that report no delinquency. Use a significance level of α = 0.05 and the information below.
No Delinquency 
Delinquent 
n = 21 
n = 5 
s_{1} = 0.6 
s_{2} = 1.6 
x_{1} = 13 
x_{2} = 17 
Would the alternative hypothesis for this test be directional or nondirectional?
27. Let’s say we believe that deskofficers and patrolofficers spend different get differing numbers of overtime hours because of their different assignments. We take a small sample of each group to determine if they are truly different. Conduct a two mean hypothesis test to ascertain whether there is a difference between deskofficers and patrolofficers regarding overtime. Use a significance level of α = 0.01 and the information below.
Desk Officers 
Patrol Officers 
n = 4 
n = 7 
s_{1} = 2.9 
s_{2} = 2.0 
$$ x ¯ 1 = 3

$$ x ¯ 2 = 5

What do you conclude?
28. Let’s say we believe that deskofficers and patrolofficers spend different get differing numbers of overtime hours because of their different assignments. We take a small sample of each group to determine if they are truly different. Conduct a two mean hypothesis test to ascertain whether there is a difference between deskofficers and patrolofficers regarding overtime. Use a significance level of α = 0.01 and the information below.
Desk Officers
Patrol Officers
n = 4
n = 7
s_{1} = 2.9
s_{2} = 2.0
What is your critical value(s) for this test?
29. Let’s say we believe that deskofficers and patrolofficers spend different get differing numbers of overtime hours because of their different assignments. We take a small sample of each group to determine if they are truly different. Conduct a two mean hypothesis test to ascertain whether there is a difference between deskofficers and patrolofficers regarding overtime. Use a significance level of α = 0.01 and the information below.
Desk Officers
Patrol Officers
n = 4
n = 7
s_{1} = 2.9
s_{2} = 2.0
What is the degrees of freedom for this test?
30. What are the age differences among teens that report being delinquent (or not)? Conduct a two mean hypothesis test to ascertain whether there is an age difference between teens who report being delinquent and teens that report no delinquency. Use a significance level of α = 0.05 and the information below.
No Delinquency
Delinquent
n = 21
n = 5
s_{1} = 0.6
s_{2} = 1.6
What is your obtained t?