State	BTU (millions)
Rhode Island	172.9
New York	179.5
California	201.1
Hawaii	201.6
Connecticut	203.3
Vermont	205.9
Massachusetts	208.6
Florida	210.4
New Hampshire	214.8
Arizona	214.8
Nevada	232.4
Maryland	235.6
Oregon	252.8
North Carolina	254.7
New Jersey	256.2
District of Columbia	267.2
Michigan	273.7
Utah	277.5
Colorado	279.9
Georgia	281.5
Pennsylvania	284.4
Maine	285.4
Virginia	287.7
Delaware	298.3
Washington	298.3
Illinois	300.3
Missouri	300.9
Wisconsin	302.9
Ohio	319.1
Tennessee	324.9
Idaho	325.4
New Mexico	329.7
South Carolina	332.6
Minnesota	339.1
Arkansas	360.8
Mississippi	379.5
West Virginia	389.2
Montana	389.5
Kansas	390.4
Alabama	395.4
Oklahoma	411.1
Indiana	426.1
Kentucky	427.1
South Dakota	451.3
Nebraska	463.8
Texas	471.3
Iowa	471.4
North Dakota	788.4
Louisiana	849.3
Alaska	872.7
Wyoming	948.5

a) What proportion of these states has per capita energy consumption within +-1 standard devation of the mean, within +-2 standard devation of the mean, and within +-3 standard devation of the mean?

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