Based on tests of the Chevrolet Cobalt engineers have found

Based on tests of the Chevrolet Cobalt, engineers have found that the miles per gallon in highway driving for all of these cars averages 32 miles per gallon with a standard deviation of 3.5 miles per gallon. If consider samples of 16 cars, then the mean of the sample means and standard deviation of the sample means will be:

Solution

mean = 32

standard deviation = 3.5 / srqt 16 = 0.875