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STA 2023
Practice Questions
Final Exam
1. Which of the following is not
a property of the t distribution?
a) has fatter tails than a Z distribution
b) it is symmetric and mound shaped
c) it is centered at zero
d) as the degrees of freedom increase it becomes less like a Z distribution.
Questions 2 – 5
An education researcher has developed a new technique to
teach Spanish to high school students. To prove this new method is better, she
will teach two groups of students for an entire semester, one with the new
method and one with the standard method used today in high schools. She
wishes to obtain 12 sets of identical twins, 24 people total, and split the twins
up so that one of each twin is in Class 1, which will receive the new technique,
and one is in Class 2, which will receive the old technique. At the end of the
semester both classes will take a standardized exam and the results will be
compared.
2. What method should be used to analyze this data?
a) one mean
b) two independent means
c) matched pairs
d) two independent proportions
3. What should our hypotheses be to test if your new method is better than the
old method?
a) H
0
:
μ
1
μ
2
= 0 vs. H
A
:
μ
1
μ
2
< 0
b) H
0
:
μ
D
= 0 vs. H
A
:
μ
D
< 0
c) H
0
:
μ
1
μ
2
= 0 vs. H
A
:
μ
1
μ
2
0
d) H
0
:
μ
D
= 0 vs. H
A
:
μ
D
0
4. What distribution would you use to look up the p value for this test of
hypothesis?
a) t(11)
b) t(12)
c) t(23)
d) Z
5. Suppose we collect the data from this experiment and we find a p value of
0.009. Which of the following is our conclusion at any reasonable alpha level?
a) There is no difference between the two educational methods.
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View Full Documentb) The old method is better than the new method.
c) The new method is better than the old method.
d) We cannot determine without more information.
Questions 6 8 use the following modifications to the above scenario.
Unable to obtain the 12 sets of twins to conduct the experiment, the researcher
has to use two existing Spanish classes at a local high school, one with 12
students and the other one with 11 students.
6. What method should be used to analyze this data?
a) one mean
b) two independent means
c) matched pairs
d) two independent proportions
7. What should our hypotheses be to test if your new method is better than the
old method?
a) H
0
:
μ
1
μ
2
= 0 vs. H
A
:
μ
1
μ
2
< 0
b) H
0
:
μ
D
= 0 vs. H
A
:
μ
D
< 0
c) H
0
:
μ
1
μ
2
= 0 vs. H
A
:
μ
1
μ
2
0
d) H
0
:
μ
D
= 0 vs. H
A
:
μ
D
0
8. What distribution would you use to look up the p value for this test of
hypothesis?
a) t(11)
b) t(10)
c) t(23)
d) Z
9. What distribution would Minitab use to find the p value for this test of
hypothesis?
a)
t with more degrees of freedom than we use
b) t with less degrees of freedom than we use
c)
t with same degrees of freedom we use
d) Z
Questions 10 – 13
We suspect that men are convicted of DUI (driving under the
influence of alcohol or drugs) more often than women. Let p
1
be the proportion
of males convicted of a DUI offense and p
2,
the proportion of females convicted
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 Spring '08
 Ripol
 Statistics

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