Posted: April 28th, 2017

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).

he EPA claims that fluoride in children’s drinking water should be at a mean level of less than 1.2 ppm, or parts per million, to reduce the number of dental cavities. Identify the Type I error. (Points : 1)
Fail to support the claim σ < 1.2 when σ < 1.2 is true.

Support the claim μ < 1.2 when μ = 1.2 is true.

Support the claim σ < 1.2 when σ = 1.2 is true.

Fail to support the claim μ < 1.2 when μ < 1.2 is true.

2.
Medical researchers studying two therapies for treating patients infected with Hepatitis C 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.
Therapy 1
Therapy 2
Number of patients
39
47
Eliminated Hepatitis
20
13
C infection
Construct a 95% confidence interval estimate of the odds ratio of the odds for having Hepatitis C after Therapy 1 to the odds for having Hepatitis C after Therapy 2. Give your answer with two decimals, e.g., (12.34,56.78) (Points : 0.5)
0.3
3.Researchers studying sleep loss followed the length of sleep, in hours, of 10 individuals with insomnia before and after cognitive behavioral therapy (CBT). Assume a .05 significance level to test the claim that there is a difference between the length of sleep of individuals before and after CBT. 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
1
2
3
4
5
6
7
8
9
10
Before
6
5
4
5
3
4
5
3
4
2
CBT

After
8
8
7
6
7
6
6
5
7
5
CBT

Construct a 95% confidence interval estimate of the mean difference between the lengths of sleep. Give your answer with two decimals, e.g., (12.34,56.78) (Points : 0.5)
4.
The paired data consist of the cost of regionally advertising (in thousands of dollars) a certain pharmaceutical drug and the number of new prescriptions written (in thousands).

Cost
9
2
3
4
2
5
9
10
Number
85
52
55
68
67
86
83
73

Find the predicted value of the number of new prescriptions written if $6000 is spent in regional advertising. Give your answer as an integer. (Points : 0.5)
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
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Dec
1
3
2
7
14
20
37
33
16
6
2
3

Determine the value of the χ2 test statistic. Give your answer to two decimals, e.g., 12.34 . (Points : 0.5)
6.
Using a .01 significance level, test the claim that the proportions of fear/do not fear responses are the same for male and female dental patients.

Gender

Male
Female
Fear Dentistry
48
70
Do Not Fear Dentistry
21
32

Determine the value of the χ2 test statistic. Give your answer to three decimals, e.g., 12.345 . (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.

Immune Modulator Cream

Cure
No Cure
Topical Steroid
Cure
25
11
Cream
No Cure
42
22

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)
8.
Geneticists studying carriers of genetic diseases followed subjects subdivided by race. Researchers randomly selected seven patients per race who had been identified as carrying a certain gene for a genetic disease; these patients were followed to determine the number of their siblings who also carried the gene for the genetic disease. Use a One-Way ANOVA at a .05 significance level to test the claim that the means from the different races are not all the same.

Caucasian
African-American
Other
2
0
0
3
0
1
3
1
2
3
2
2
4
2
2
5
2
3
5
4
4

Determine the value of the F test statistic. Give your answer to two decimals, e.g., 12.34 . (Points : 0.5)
9.
Question 9 of 10If there is only one observation per cell in a Two-Way ANOVA, and it can be assumed there is not an interaction between factors, then we can proceed to interpret the results of the row and column effects. (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
Df
SS
MS
F
P
Site
2
.1905
.0952
.0381
.9627
Habitat
1
304.0238
304.0238
121.6095
.0000
Site*Habitat
2
.1905
.0952
.0381
.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)