The manufacturers of Cortez automotive oil wish to estimate the mean number of miles that motorist drive between oil changes. A random sample of 54 motorists has a mean of 5900 miles driven between oil changes. Assume that the population standard deviation is 1350 miles. Construct and interpret a 95% confidence interval estimate for the mean number of miles driven between oil changes.

Define the population of interest and select a simple random sample.

Specify the confidence level

Compute the sample mean

Determine the standard error of the sampling distribution. Determine the critical value, z, from the standard normal distribution table.