I don't know how to solve this question, can someone explain it to me. Also, can you show your work so I know how to do it. Thank you :-)

2. A professor records the time in minutes that it takes 8 students to complete an exam. Compute the mean, variance, and standard deviation, assuming that the 8 students constitute the population (8 pts) 25 50 43 39 26 39 37 41 3. Decide whether to reject or fail to reject the null hypothesis using 042-tailed) = .05 for the following (3 points) a. Zobt = 1.39 Reject Fail to reject b. Zobt = -1. 97 Reject Fail to reject C. tobe = +2.50, p(sig.) = .021 Reject Fail to reject d. tobt = -1.39, p(sig.) = .21 Reject Fail to reject e. Fob = 3.25, p(sig) = .039 Reject Fail to reject f. Fobt = 19.14, p(sig.) = .003 Reject Fail to reject