A random sample of 16 people spent an average of 45 minutes driving to work. Assume the population standard deviation (?) is known and equals 8, find a 95% confidence interval for the population mean...

A random sample of 16 people spent an average of 45 minutes driving to work.

1. Assume the population standard deviation (?) is known and equals 8, find a 95% confidence interval for the population mean (μ)


2. Assume the population standard deviation (?) is unknown and the sample standard deviation (s) equals 8, find a 95% confidence interval for the population mean (μ)