Prisons 2006 A report from the U.S. Department of Justice (www.ojp.usdoj.gov/bjs/) reported the percent changes in federal prison populations in 21 northeastern and midwestern states during 2006. Using appropriate graphical displays and summary statistics, write a report on the changes in prison populations.

Confidence Interval Sample statistic Usually a point estimate Used to estimate population parameter Sample point estimate +/- margin of error Lower endpoint sample point estimate upper endpoint Margin of error Margin of error Measure of variability associated with point of estimate at desired level of confidence Small margin of error means higher precision Higher desired confidence level means a larger margin of error Lowest value in the computed confidence level =lower endpoint Highest value in the computed confidence level= higher endpoint Confidence interval for p Point estimate +/- margin of error Margin of