Question: The data in the file ENERGY contains the per capita energy consumption in kilowatt hours for each of the 50 states and the District of Columbia during 1999.

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

(b) What proportion of these states has average per capita energy consumption within ±1 standard deviation of the mean, within ±2 standard deviations of the mean, and within ±3 standard deviations of the mean?

(c) Compare and contrast your findings versus what would be expected based on the empirical rule. Are you sur­prised at the results in (b)?

(d) Do (d) through (c) with the District of Columbia removed. How have the results changed?