A. You have just recorded the waiting times for a random sample of 50 customers who

visited Domino's Pizza Shop. The following table gives the frequency distribution of

waiting times (in minutes) for these customers.

Waiting Time f

10 to less than 16 6

16 to less than 22 10

22 to less than 28 15

28 to less than 34 11

34 to less than 40 7

40 to less than 46 1

i). The mean waiting time, rounded to two decimal places, is:

ii). The variance of waiting times is:

iii). The standard deviation of waiting times is: