Question

1. Independent simple random samples are taken to test the difference between the means of two populations whose variances are not known. Given the sample sizes are n₁ = 11 and n₂ = 16; and the sample variances are S₁² = 33 and S₂² = 64, what is the correct distribution to use for performing the test?

   	A.	t distribution with 49 degrees of freedom
   	B.	t distribution with 59 degrees of freedom
   	C.	t distribution with 24 degrees of freedom
   	D.	t distribution with 27 degrees of freedom

2.5 points

Question 8

1. Exhibit 2 (Questions 8-11)

   In order to determine whether or not there is a significant difference between the proportion of male and female executives with annual salary of at least $150,000, the following data based on two random samples have been accumulated.

                                                                Male executive Female executive

   Sample size                                                           n₁ = 80 n₂ = 60

   Annual salary of at least $150,000                          64    36

   Refer to Exhibit 2. What is the point estimate of the difference between the proportions of executives with annual salary of at least $150,000 for the two populations of male and female executives?

   	A.	0.16
   	B.	0.10
   	C.	0.20
   	D.	0.22

2.5 points

Question 9

1. Exhibit 2 (Questions 8-11)

   In order to determine whether or not there is a significant difference between the proportion of male and female executives with annual salary of at least $150,000, the following data based on two random samples have been accumulated.

                                                                Male executive Female executive

   Sample size                                                           n₁ = 80 n₂ = 60

   Annual salary of at least $150,000                          64 36

   Refer to Exhibit 2. What is the standard error of the difference between the sample proportions of male and female executives with annual salary of at least $150,000?

   	A.	0.0775
   	B.	0.0456
   	C.	0.0593
   	D.	0.3158

2.5 points

Question 10

1. Exhibit 2 (Questions 8-11)

   In order to determine whether or not there is a significant difference between the proportion of male and female executives with annual salary of at least $150,000, the following data based on two random samples have been accumulated.

                                                                Male executive Female executive

   Sample size                                                           n₁ = 80 n₂ = 60

   Annual salary of at least $150,000                          64 36

   Refer to Exhibit 2. Using a 95% confidence level, what is the margin of error for the difference between the two population proportions?

   	A.	0.191
   	B.	0.152
   	C.	0.576
   	D.	0.039

2.5 points

Question 11

1. Exhibit 2 (Questions 8-11)

   In order to determine whether or not there is a significant difference between the proportion of male and female executives with annual salary of at least $150,000, the following data based on two random samples have been accumulated.

                                                                Male executive Female executive

   Sample size                                                           n₁ = 80 n₂ = 60

   Annual salary of at least $150,000                          64    36

   Refer to Exhibit 2. What is a 95% confidence interval estimate of the difference between the population proportion of male and female executives who have an annual salary of at least $150,000?

   	A.	- 0.091 to 0.291
   	B.	1.145 to 2.145
   	C.	0.048 to 0.352
   	D.	0.032 to 0.732

Answer 1