a A sample of 400 observations taken from a population produced a sample mean equal to 92 45 and a standard deviation equal to 12 20 Make a 98 confidence interval for b Another sample of 400 observations taken from the same population produced a sample mean equal to 91 75 and a standard deviation e...

In each of the following parts since n 400 is very large we use th ...

a. A sample of 400 observations taken from a population produced a sample mean equal to 92.45

Question:

a. A sample of 400 observations taken from a population produced a sample mean equal to 92.45 and a standard deviation equal to 12.20. Make a 98% confidence interval for µ
b. Another sample of 400 observations taken from the same population produced a sample mean equal to 91.75 and a standard deviation equal to 14.50. Make a 98% confidence interval for µ
c. A third sample of 400 observations taken from the same population produced a sample mean equal to 89.63 and a standard deviation equal to 13.40. Make a 98% confidence interval for µ
d. The true population mean for this population is 90.65. Which of the confidence intervals constructed in parts a through c cover this population means and which do not?