SCENARIO 10-10 A corporation randomly selects 150 salespeople and finds that 66% who have never taken a self- improvement course would like such a course.The firm did a similar study 10 years ago in which 60% of a random sample of 160 salespeople wanted a self-improvement course.The groups are assumed to be independent random samples.Let and represent the true proportion of workers who would like to attend a self-improvement course in the recent study and the past study, respectively.
-Referring to Scenario 10-10, what is/are the critical value(s)when performing a Z test on whether population proportions are different if = 0.05?
A) 1.645
B) 1.96
C)-1.96
D) 2.08

Question

SCENARIO 10-10 A corporation randomly selects 150 salespeople and finds that 66% who have never taken a self- improvement course would like such a course.The firm did a similar study 10 years ago in which 60% of a random sample of 160 salespeople wanted a self-improvement course.The groups are assumed to be independent random samples.Let  and  represent the true proportion of workers who would like to attend a self-improvement course in the recent study and the past study, respectively.
-Referring to Scenario 10-10, what is/are the critical value(s)when performing a Z test on whether population proportions are different if  = 0.05?
A) 1.645 
B) 1.96 
C)-1.96 
D) 2.08

Quizplus · Accepted Answer

When performing a z-test for the difference between two population proportions, the critical value for a 95% confidence level (with a two-tailed test) is 1.96. Since the question asks for the critical value when alpha = 0.05, which corresponds to a 95% confidence level, the answer is B, 1.96. When performing a two-tailed Z test on whether population proportions are different, with a significance level of 0.05, the critical value is 1.96. Since the groups are assumed to be independent random samples, we can use the standard normal distribution to calculate the critical value. Thus, the correct answer is B) 1.96.

SCENARIO 10-10 a Corporation Randomly Selects 150 Salespeople and Finds