Exhibit 8-4 In Order to Estimate the Average Electric Usage Per Month,a

Multiple Choice

Exhibit 8-4
In order to estimate the average electric usage per month,a sample of 81 houses was selected,and the electric usage was determined.Assume a population standard deviation of 450-kilowatt hours.
-Refer to Exhibit 8-4.If the sample mean is 1,858 KWH,the 95% confidence interval estimate of the population mean is

A) 1,760 to 1,956 KWH
B) 1,858 to 1,956 KWH
C) 1,760 to 1,858 KWH
D) None of these alternatives is correct.