Question

A social researcher is interested in understanding the effect of college education on wages. The workers in one group have earned an associate’s degree while members of the other group hold at least a bachelor’s degree. He would like to run a hypothesis test with α = .10 to see if those with a bachelor’s degree have significantly higher hourly wages than those with an associate’s degree.

Bachelor’s degree			Associate’s degree
Participant	Hourly wage		Participant	Hourly wage
1	11.25		11	10.25
2	12.25		12	11.25
3	11.60		13	9.10
4	9.80		14	10.00
5	9.40		15	9.70
6	12.60		16	11.00
7	11.80		17	10.10
8	12.70		18	9.40
9	11.90		19	9.20
10	14.10		20	10.50

a. Calculate standard deviation of the comparison distribution

1. Calculate the t statistic (2 points total: 1 for work and 1 for result)

2. Considering the research question and the hypotheses, should the test be one-tailed or two-tailed? Why? (2 points total: 1 for each answer)

3. Determine the critical t value(s) for this hypothesis test based on the degree of freedom, from (d), and the preset alpha level. (1 point total)

4. Compare the calculated t statistic with the critical t value by stating which is more “extreme”, and then make a decision about the hypothesis test by stating clearly “reject” or “fail to reject” the null hypothesis. (1 point total: .5 for comparison, .5 for decision)

e. Calculate the pooled standard deviation for the populations and then use it to calculate the standardized effect size of this test.

Answer 1