The file S02_09.xlsx lists the times required to service 200 consecutive customers at a (fictional) fast-foods restaurant.
a. Create a histogram of the customer service times.
How would you characterize the distribution of service times?
b. Calculate the mean, median, and first and third quartiles of this distribution.
c. Which measure of central tendency, the mean or the median, is more appropriate in describing this distribution? Explain your reasoning.
d. Find and interpret the variance and standard deviation of these service times.
e. Are the empirical rules for standard deviations applicable for these service times? If not, explain why. Can you tell whether they apply, or at least make an educated guess, by looking at the shape of the histogram? Why?