You want to estimate the average life of a new kind of computer chip. You take a sample of 16 chips and find the sample mean to be 12.50 years with a...

You want to estimate the average life of a new kind of computer chip. You take a sample of 16 chips and find the sample mean to be 12.50 years with a sample standard deviation of .80 years. You construct a 99% two-sided confidence interval estimate. It is: