A simple random sample with n=52 provided a sample mean of 21.0 and a sample standard deviation of 4.2. a. Develop a 90% confidence interval for the population mean (to 1 decimal). , b. Develop a 95%...

A simple random sample with n=52 provided a sample mean of  21.0 and a sample standard deviation of 4.2.

a.
Develop a  90% confidence interval for the population mean (to 1 decimal).

  ,

b.
Develop a  95% confidence interval for the population mean (to 1 decimal).

  ,

c.
Develop a  99% confidence interval for the population mean (to 1 decimal).