posted by b on .
any state auto insurance company took a random sample of 370 insurance claims paid out during a 1-year period. the average claim was $750 with a standard deviation of $150. find .99 confidence interval for the mean claim payment.
CI99 = mean ± (z-value)(sd/√n)
mean = 750
sd = 150
n = 370
Find the z-value using a z-table for 99% confidence, then calculate your interval.
I hope this will help get you started.