A marketing research company desires to know the mean consumption of milk per week among males over age 25. A sample of 513 males over age 25 was drawn and the mean milk consumption was 2.9 liters. Assume that the population standard deviation is known to be 1.1 liters. Construct the 85% confidence interval for the mean consumption of milk among males over age 25. Round your answers to one decimal place.

Answer:Confidence interval for the mean consumption of milk per week among males over age 25 in 85% confidence level is (2.8≤μ≤3.0)Step-by-step explanation:Consumption of milk among males over age 25 can be found using the formula:M±[tex]z*\frac{s}{\sqrt{N} }[/tex]  where M is the sample mean, z is the corresponding z-score for 85% confidence level, s is the population standard deviation, N is the sample size. In this sample, mean of milk consumption per week among males over age 25 is 2.9 liters. Corresponding z-score for 85% confidence interval is 1.440. standard deviation of the sample is 1.1. And sample size is 513. When we put these numbers in the formula, we got:2.9±[tex]1.440*\frac{1.1}{\sqrt{513} }[/tex] =2.9±0.07