The file McDonaldsStores contains the number of McDonald’s stores located in each of the 50 U.S. states and the District of Columbia, as of December 31, 2016:

Source: Data extracted from bit.ly/2qJjFpF.

a. Compute the mean, variance, and standard deviation for this population.

b. What percentage of the 50 states have a number of McDonald’s stores within ±1, ±2, or ±3 standard deviations of the mean?

c. Compare your findings with what would be expected on the basis of the empirical rule. Are you surprised at the results in (b)?