A social worker is interested in estimating the average length of time spent outside of prison for first offenders who later commit a second crime and are sent to prison again. A random sample of 120 prison records in the county courthouse indicates that the average length of prison-free life between and second offenses is 3.2 years, with a standard deviation of 1.1 years. Use the sample information to construct 95% and 99% confidence intervals for the mean prison free life between first and second offenses for all prisoners on record in the county courthouse.
What is the lower limit of the 95% interval? Give your answer to three decimal places.
What is the upper limit of the 95% interval? Give your answer to three decimal places.
What is the lower limit of the 99% interval? Give your answer to three decimal places.
What is the upper limit of the 99% interval? Give your answer to three decimal places.