The data for daily energy usage of a small town during ten days in January is shown. 83.8 MWh 87.1 MWh 92.5 MWh 80.6 MWh 82.4 MWh 77.6 MWh 78.9 MWh 78.2 MWh 81.8 MWh 80.1 MWh
b. How many values in the data set fall within one standard deviation from the mean? Within two standard deviations? Within three standard deviations?