4. The time it takes to turn in a homework assignment is assumed to be normally distributed. A random sample of 15 students was selected and the time (days) it took for each one to turn in their most recent homework assignment is as follows: {6, 6, 2, 3, 10, 2, 4, 4, 5, 3, 6, 6, 5, 4, 6}.

a. Find a point estimate for the typical number of days it takes students to hand in their homework assignment

b. Construct a 90% confidence interval for the mean number of days and interpret