In a sample of 250 petitioners who filed for nonbusiness bankruptcy between January 2008 and December 2010 (out of 221,956 such petitioners), the sample average number of months taken to acquire the debts listed on the petitions was 35.41 with a sample standard deviation of 21.34.
a. Compute a 99% confidence interval for the true average number of months taken by bankruptcy petitioners to acquire debts listed on their petitions.