A small engine shop receives an average of 17 repairs per ho

A small engine shop receives an average of 1.7 repairs per hour, with a standard deviation of 0.6. What is the mean and standard deviation of the number of calls they receive for an 8-hour day? What, if anything did you assume?

Solution

Mean is 1.7 repairs per hour.

For 8 hour day the mean is (1.7)8 = 13.6

Standard deviation is 8(0.6) = 4.8

We assume that calls received in an hour is iindependent of calls received in next hour