Question

According to data on the state of Iowa, the amount of water used for cooking per household per month is normally distributed, with a standard deviation of 10.4 liters. A survey was carried out to estimate the population mean. With a sample size of 60 households, the mean quantity of water used for cooking was found to be 62.6 liters. What can we say about the population mean? 1. There is a 95% chance that the population mean would lie between 59.91 liters and 65.29 liters. 2 There is a 95% chance that the population mean would lie between 61.11 liters and 65.09 liters.

Answer 1

95% confidence interval = 62.6 + or - 1.96 x 10.4/sqrt(60) = 62.6 + or - 1.96 x 1.343 = 62.6 + or - 2.63.

Therefore, there is a 95% chance that the population mean would lie between 59.91 liters and 65.29 liters.