According to a government energy agency, the mean monthly household electricity bill in the United States in2011

Electricity bills: According to a government energy agency, the mean monthly household electricity bill in the United States in 2011 was $108.87. Assume the amounts are normally distributed with standard deviation $21.00. Use the TI-84 Plus calculator to answer the following. (a) Find the 10th percentile of the bill amounts. (b) Find the 67th percentile of the bill amounts. (c) Find the median of the bill amounts. Round the answers to at least two decimal places. How much do you study? A survey among freshmen at a certain university revealed that the number of hours spent studying the week before nal exams was normally distributed with mean 26 and standard deviation 6. Use the TI-84 PLUS calculator to answer the following. Round the answers to at least two decimal places. . th _ . (a) FInd the 97 percentile of the number of hours studying. (b) Find the 32nd percentile of the number of hours studying. (c) Between what two values are the middle 84% of the hours spent studying? Tire lifetimes: The lifetime of a certain type of automobile tire (in thousands of miles) is normally distributed with mean u = 12.06 and standard deviation 6 = 0.03. Round the answers to at least three decimal places. (a) Find the 90th percentile of the tire lifetimes. (b) Find the 3rd percentile of the tire lifetimes. (c) Between what two values are the middle 95% of the tire lifetimes