Twenty people in one large metropolitan area were asked to record the time (in minutes) that it

Question:

Twenty people in one large metropolitan area were asked to record the time (in minutes) that it takes them to drive to work. These times were as follows:
30 42 35 40 45 22 32 15 41 45
28 32 45 27 47 50 30 25 46 25
a. Calculate the standard error.
b. Find tv,α/2 for a 95% confidence interval for the true population mean.
c. Calculate the width for a 95% confidence interval for the population mean time spent driving to work.