Question: A study was conducted to estimate costs for accident victims who wear seat belts. Twenty selected cases have a distribution that appears to be normal with a mean of $9,004 and SD of $5629.

a) Construct a 99% CI for the means of all such costs.

b) If you are a manager of an insurance company that provides lower rates for drivers who wear seat belts and you want a conservative estimate for a worst case scenario, what amount should you use as the hospital cost for an accident victim who wears seat belt?