Electricity bills: According to a government energy agency, the mean monthly household electricity bill in the United States in 2011 was $109.88. Assume the amounts are normally distributed with standard deviation $18.00. Use the TI-84 Plus calculator to answer the following. (a) Find the 8th percentile of the bill amounts. (b) Find the 63rd percentile of the bill amounts. (c) Find the median of the bill amounts. Round the answers to at least two decimal places