The standard deviation of the diameter at breast height

The standard deviation of the diameter at breast height, or DBH, of the slash pine tree is less than one
inch. Identify the Type I error. (Points : 1)
Fail to support the claim σ < 1 when σ < 1 is true.

Support the claim μ < 1 when μ = 1 is true.

Support the claim σ < 1 when σ = 1 is true.

Fail to support the claim μ < 1 when μ < 1 is true.

2.

Use the following sample sizes and numbers of successes for this question.
Medical researchers reviewing the risk of death for elderly patients taking dementia drugs found the
following data. Assume a .05 significance level for testing the claim that the proportions are not equal.
Also, assume the two simple random samples are independent and that the conditions np ≥ 5 and nq ≥ 5 are
satisfied.

Dementia Drugs

Placebo
500
23

Number of patients
Total deaths

450
12

Construct a 95% confidence interval estimate of the odds ratio of the odds for death in the placebo group to the odds
for death in the dementia drugs group. Give your answer with two decimals, e.g., (12.34,56.78) (Points : 0.5)

3.

Ophthalmologists studying the treatment of using an infrared laser procedure in ten patients with vision
loss caused by dry age-related macular degeneration (AMD) found the following data on visual acuity (VA)
before and after the procedure. Assume a .05 significance level to test the claim that there is a difference
between the number of VA lines that can be read by individuals before and after the procedure. Also,
assume the data consist of matched pairs, the samples are simple random samples, and the pairs of values
are from a population having a distribution that is approximately normal.

Individual
VA Lines Read Before
Laser Procedure
VA Lines Read After
Laser Procedure

1
3

2
4

3
2

4
4

5
5

6
3

7
4

8
5

9 10
3 3

4

4

5

5

6

3

7

6

3

Find the t test statistic. Give your answer with two decimals, e.g., 9.87 . (Points : 0.5)

5

4.

Given: There is a linear correlation coefficient very close to 0 between mothers who smoked during
pregnancy and the incidence of influenza in their babies. Identify the choice below that contains a
conclusion with a common correlation error. (Points : 1)
Conclusion: the frequency of mothers' smoking is not related in any way to the incidence of influenza in

their babies
Conclusion: an increase in the frequency of mothers' smoking is not linearly related to an increase in the
incidence of influenza in their babies
Conclusion: a decrease in the frequency of mothers' smoking is not linearly related to a decrease in the
incidence of influenza in their babies
Conclusion: there is not a linear relationship between the frequency of mothers' smoking and the incidence
of influenza in their babies
5.

Use a .05 significance level and the observed frequencies of 144 drownings at the beaches of a randomly
selected coastal state to test the claim that the number of drownings for each month is equally likely.

Jan

Feb
1

Mar
3

Apr
2

7

May June July
Aug
Sept
Oct
Nov
Dec
14
20
37
33
16
6
2
3

Do you reject the null hypothesis, at the .05 significance level? Enter Y for yes (reject), N for no (fail to reject).
(Points : 0.5)

6.

Using a .01 significance level, test the claim that the proportions of people who favor/oppose pro-choice
on the abortion issue are the same for the males and females.
Gender

Favor Pro-Choice
Oppose Pro-Choice

Male
65
42

Female
120
38

Determine the value of the χ2 test statistic. Give your answer to two decimals, e.g., 12.34 . (Points : 0.5)

7.

The table represents results from an experiment with patients afflicted with eczema on both arms. Each
patient was treated with an immune modulator cream on one arm and a topical steroid cream on the other
arm. Using a .05 significance level, apply McNemar's test to test the following claim: The proportion of
patients with no cure on the immune modulator treated arm and a cure on the topical steroid treated arm is
the same as the proportion of patients with a cure on the immune modulator treated arm and no cure on the
topical steroid treated arm.

Topical Steroid
Cream

Cure
No Cure

Immune Modulator Cream
Cure
25
42

No Cure
11
22

Determine the value of the χ2 test statistic. Give your answer to two decimals, e.g., 12.34 (Points : 0.5)

8.

For a study on Type 1 diabetes, medical graduate students subdivided the United States into four study
regions (Northeast, Southeast, Southwest, and Northwest). The students randomly selected seven patients
per region and recorded the number of times during a randomly selected month that each patient used
insulin shots to regulate blood sugar levels. Use One-Way ANOVA at a .05 significance level to test the
claim that the means from the different regions are not the same.
Mean number of times patients used insulin shots to regulate blood sugar levels
Northeast
Southeast
Southwest
Northwest
4
6
4
4
3
5
5
4
3
6
6
5
4
8
6
6
3
6
7
3
2
6
5
5
5
8
4
3

Determine the value of the F test statistic. Give your answer to two decimals, e.g., 12.34 . (Points : 0.5)

9.

One method to reduce the effect of extraneous factors is to design the experiment so that it has a
convenience sampling design. (Points : 1)
True

False

10. Use the following technology display from a Two-Way ANOVA to answer this question. Biologists
studying habitat use in Lepidopteran moths measured the number of savannah moths found at three
randomly selected prairie sites with two potential habitat interferences (expansion of row crops and
grazing). Use a .05 significance level.

Source
Site
Habitat
Site*Habitat

Df
2
1
2

SS

MS
.1905
304.0238
.1905

F
.0952
304.0238
.0952

.0381
121.6095
.0381

P
.9627
.0000
.9627

Do you reject the null hypothesis about the site effect, at the .05 significance level? Enter Y for yes (reject), N for
no (fail to reject). (Points : 0.5)