Instruction 10-12
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 π 1 and π 2 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 Instruction 10-12,what is/are the critical value(s)when testing whether the current population proportion is higher than before if α = 0.05?
A) + 1.96
B) ± 1.645
C) + 1.645
D) ± 1.96

Question

Quizplus · Accepted Answer

To test if the current population proportion is higher than before, we use a one-tailed test with the alternate hypothesis being that π₁ > π₂. Since the sample sizes are large and we know the population standard deviation, we can use a z-test. The critical value for a one-tailed test with α = 0.05 is 1.645. Therefore, we reject the null hypothesis and conclude that the current population proportion is higher than before if the z-statistic calculated from the sample data is greater than 1.645.

Instruction 10-12 A Corporation Randomly Selects 150 Salespeople and Finds That 66