The U.S. Department of Justice, Office of Justice Programs, and 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 theWeissStats 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.