The wait times of 2444 patients at 18 health care clinics in the Wake Forest University Baptist Medical Center located in Winston-Salem, North Carolina, were studied. The mean wait time was 21.0 minutes with standard deviation 14.7 minutes.
a. Explain why the wait-time distribution cannot be normal or even approximately normal.
b. On the basis of the mean, standard deviation, and your explanation in part (a), determine whether the wait-time distribution is skewed left, skewed right, or symmetric.
c. For the purposes of the study, it was reasonable to exclude patients who had wait times greater than 75 minutes. A total of 91 such patients were excluded. How would the mean wait time and standard deviation have changed if the 91 patients had been included in the study? Explain.