# Stats Exam 5

Pages: 13 (1534 words) Published: July 22, 2012
Question 1 of 10
1.0 Points
A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. Using   = .05, what is the value the test statistic?

Women
Men
Sample size
50
80
Mean effect
7
6.95
Sample variance
3
4

A. t = 3.252

B. z = 0.455

C. z = 0.081

D. z = 0.151

Question 2 of 10
1.0 Points

A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the .10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree?

Pine trees
Spruce trees
Sample size
40
70
Mean trunk diameter (cm)
45
39
Sample variance
100
150

A. The data do not support the claim because the test value 1.29 is greater than 1.28.

B. The data support the claim because the test value 2.78 is greater than 1.28.

C. The data support the claim because the test value 2.78 is greater than 1.64.

D. The data do not support the claim because the test value 1.29 is less than 1.64.

Question 3 of 10
1.0 Points
A researcher hypothesizes that the variation in the amount of money spent on business dinners is greater than the variation of the amount of money spent on lunches. The variance of nine business dinners was \$6.12 and the variance of 12 business lunches was \$0.87. What is the test value?

A. 3.10

B. 9.61

C. 49.50

D. 7.03

Question 4 of 10
1.0 Points
Members of the general adult population volunteer an average of 4.2 hours per week. A random sample of 20 female college students and 18 male college students produced the results given in the table below. At the .01 level of significance, is there sufficient evidence to conclude that a difference exists between the mean number of volunteer hours per week for male and female college students?

Females
Males
Sample size
20
18
Sample mean
3.8
2.5
Sample variance
3.5
2.2

A. No, because the test value 2.38 is greater than the critical value

B. No, because the test value 2.38 does not exceed the critical value

C. No, because the test value 2.90 is greater than the critical value

D. Yes, because the test value 2.90 is greater than the critical value

Question 5 of 10
1.0 Points
Consider the following scenario in answering questions 5 through 7.
Multiple myeloma or blood plasma cancer is characterized by increased blood vessel formulation in the bone marrow that is a prognostic factor in survival. One treatment approach used for multiple myeloma is stem cell transplantation with the patient’s own stem cells. The following data represent the bone marrow microvessel density for a sample of 7 patients who had a complete response to a stem cell transplant as measured by blood and urine tests. Two measurements were taken: the first immediately prior to the stem cell transplant, and the second at the time of the complete response. Use these data to answer questions 5 through 7.

Patient
1
2
3
4
5
6
7
Before
158
189
202
353
416
426
441
After
284
214
101
227
290
176
290

Perform an appropriate test of hypothesis to determine if there is evidence, at the .05 level of significance, to support the claim that the mean bone marrow microvessel density is higher before the stem cell transplant than after the stem cell transplant? What is the value of the sample test statistic?

A. z = 1.8424

B. t = 1.8424

C. t = 2.7234

D. p = 2.7234

Question 6 of 10
1.0 Points
Multiple myeloma or blood plasma cancer is characterized by...