Non-Computer Problems

1.College financial aid offices expect students to use summer earnings to help pay for college.

But how large are these earnings? One college studied this question by asking a sample of students how much they earned. Omitting students who were not employed, 1296 responses were received. (dollar figures are expressed in thousands)

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Group n X s

Males 675 $18.85 $13.68

Females 621 $13.60 $10.37

Were the mean summer earnings significantly higher for males than they were for females? Use a 5% significance level. Show your work for all 4 steps in hypothesis testing. Be sure to include diagrams and to determine and interpret the p-value for your test-statistic. State in words what the conclusion you reach from the hypothesis test suggests about the answer to the italicized question.

2. FIU is interested in the effectiveness of teacher training classes on the quality of instruction in

discussion sections.The administrators have decided to use a study with a matched, experimental design to explore this problem.Thirty professors took an intensive teacher-training

class before the Fall '14 semester began and they were paired with professors teaching the same courses who did not take the intensive training class.Course evaluations were compared at the end of the semester, and the mean advantage for those who took the course compared to their matched counterparts was 1 point on ratings of the question "The instructor is an excellent teacher." The standard deviation of this difference was 2.5.Do teacher training classes improve teaching evaluations? Use a 1% significance level. Show your work for all 4 steps in hypothesis testing. Be sure to include diagrams and to determine and interpret the p -value for your test- statistic. State in words what the conclusion you reach from the hypothesis test suggests about the answer to the italicized question.