Consider the following sample of nine wait times measured in seconds at a drive through coffee shop. The population mean and standard deviation are 100 and 20 respectively.
125 95 66 116 99 91 102 51 110
a. What is the size of the sampling error in this case?
b. What is the probability that the average wait time would be less than 80 seconds?
c. What is the probability that the average wait time would be more than 109 seconds?
d. What is the probability that the avrg wait time would be btwn 90 and 95 seconds?
e. What is the probability that a customer waits more than 65 seconds?
f. Calculate the sample st deviation.