For the following questions, use a=0.05. 1. A researcher wanted to see whether there was a...

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For the following questions, use a=0.05. 1. A researcher wanted to see whether there was a difference between students in their first year and students in their second year in stress level in the middle of the semester. He collected two samples and measured the stress levels of all the subjects using a measurement he developed. Sample #1 (of students in their first year) contained 20 students (n=20), the mean stress level was M1-83, and the sample's variance was S=7. Sample #2 (of students in their second year) contained 24 students (n-24), the mean stress level was M-79, and the sample's variance was S=8. a. Conduct a hypothesis test on these data. (10 points) b. Compute the estimated Cohen's d. (3 points) 2. Another researcher was interested in the same question, but decided to conduct a longitudinal study, using a repeated-measures design. She used a sample of 16 students, measured their stress levels in their first year of college, and then measured their stress levels once again when they were in their second year. These were here results: Subject A Stress level in first year Stress level in second year 55 65 B 70 68 C 79 75 D 76 75 E 93 94 F 84 80 G 88 75 H 77 76 | 68 72 J 81 78 K 84 76 L 87 80 M 62 65 N 90 87 78 75 85 80 P a. Conduct a hypothesis test using the data above. (10 points) b. Compute a 95% confidence interval to the mean difference. (4 points) c. Another researcher hypothesized that students experience more stress in their first year than in their second year and decided to conduct a one-tailed hypothesis test on the data above. Conduct a one- tailed hypothesis test to test his hypothesis. (Hint: use some of your work for question 2(a)). (6 points) For the following questions, use a=0.05. 1. A researcher wanted to see whether there was a difference between students in their first year and students in their second year in stress level in the middle of the semester. He collected two samples and measured the stress levels of all the subjects using a measurement he developed. Sample #1 (of students in their first year) contained 20 students (n=20), the mean stress level was M1-83, and the sample's variance was S=7. Sample #2 (of students in their second year) contained 24 students (n-24), the mean stress level was M-79, and the sample's variance was S=8. a. Conduct a hypothesis test on these data. (10 points) b. Compute the estimated Cohen's d. (3 points) 2. Another researcher was interested in the same question, but decided to conduct a longitudinal study, using a repeated-measures design. She used a sample of 16 students, measured their stress levels in their first year of college, and then measured their stress levels once again when they were in their second year. These were here results: Subject A Stress level in first year Stress level in second year 55 65 B 70 68 C 79 75 D 76 75 E 93 94 F 84 80 G 88 75 H 77 76 | 68 72 J 81 78 K 84 76 L 87 80 M 62 65 N 90 87 78 75 85 80 P a. Conduct a hypothesis test using the data above. (10 points) b. Compute a 95% confidence interval to the mean difference. (4 points) c. Another researcher hypothesized that students experience more stress in their first year than in their second year and decided to conduct a one-tailed hypothesis test on the data above. Conduct a one- tailed hypothesis test to test his hypothesis. (Hint: use some of your work for question 2(a)). (6 points)