Question

(23 pts) The JASP file ‘sleep-spring2020.csv’ contains data representing the average number of hours of sleep in the last two nights by 8 depressed patients and 9 non-depressed patients. (Group 1 is ‘depressed’ and group 2 is ‘non-depressed.’) The researcher is interested in whether the two groups reliably differ in the amount of sleep they get.

Group	Sleep
1	7.5
1	7.9
1	7.7
1	8.4
1	7.4
1	6.7
1	7.3
1	8.5
2	7
2	6.2
2	5.9
2	6.5
2	7.6
2	7.2
2	6.6
2	7.4
2	6.9

a. (2 pts) What kind of statistical test is appropriate here? Why?

b. (4 pts) What are the null and alternative hypotheses? (Make these two-tailed.)

c. (4 pts) Report the mean and sample standard deviation for each sample.

d. (3 pts) What is t_obt? How many degrees of freedom are there? What is t_crit (a = 0.05_2tail)?

Answer 1