The following frequency distribution reports the electricity

The following frequency distribution reports the electricity cost for a sample of 50 two-bedroom apartments in Albuquerque, New Mexico, during the month of May last year. Electricity Cost Frequency $ 80 up to $100 3 100 up to 120 8 120 up to 140 12 140 up to 160 16 160 up to 180 7 180 up to 200 4 Total 50 a. Estimate the mean cost. (Round your answer to 2 decimal places.) Mean cost b. Estimate the standard deviation. (Do not round intermediate calculations. Round your answer to 2 decimal places.) Standard deviation c. Use the Empirical Rule to estimate the proportion of costs within two standard deviations of the mean. What are these limits? (Round your answers to 2 decimal places.) Limits are from $ to $ .

Solution

(a) Estimate the mean cost. (Round your answer to 2 decimal places.)

Mean cost 141.20