1. A Union Wage Premium? TwoSample Univariate Hypothesis Testing

Consider a random sample of 12 construction workers, six of whom belong to a labor union and six of whom do not. The hourly wages for each worker are reported below:

Wages of union members	Wages of nonunion members
18	25
30	20
40	34
35	30
26	20
25	15

1. Test whether the population variance of one group is greater than the population variance of the other group using an F test. Test at the 5percent level of significance? What is the value of your test statistic and what is the critical value? What can you conclude and why?
2. Test whether union members in the population have higher wages than nonunion members using a ttest. What are the null and alternative hypotheses? Which version of the ttest should you use and why? What can you conclude at the 10percent level of significance? Explain.

Test of Two Proportions

Assume that students are a random sample of college students in the United States and that the assumptions of the test are true. Consider wearing a mask a "success."

	Male	Female
Number of students wearing masks	60	40
Number of students not wearing masks	20	5

Using the 10percent and 5percent levels of significance, can you conclude that there is a difference in mask-wearing by gender in the population of college students in the United States, based on the sample above?

Compute and interpret the Ztest version of this test "by hand".