up... Electricity bills: According to a government energy agency, the mean monthly household electricity bill in the United States in 2011 was $110.56. Assume the amounts are normally distributed with standard deviation $25.00. Use Excel to answer the following. Round the answer to four decimal places. (a) What proportion of bills are greater than $125? The proportion of bills that are greater than $125 is D. (b) What proportion of bills are between $83 and $143? The proportion of bills that are between $83 and $143 is E]. E