The U.S. Department of Justice, Office of Justice Programs, Bureau of Justice Statistics provides information on prison sentences in the document National Corrections Reporting Program. A random sample of 20 maximum sentences for murder yielded the data, in months, presented on the Weiss Stats site. Use the technology of your choice to do the following.

a. Find a 95% confidence interval for the mean maximum sentence of all murders. Assume a population standard deviation of 30 months.

b. Obtain a normal probability plot, boxplot, histogram, and stemand- leaf diagram of the data.

c. Remove the outliers (if any) from the data, and then repeat part (a).

d. Comment on the advisability of using the z-interval procedure on these data.