Question

Take a sample of 60 grades and test the following: 1) Test for the hypothesis that the average grade is not 75.  2) Test for the hypothesis that the average grade below is higher than 75. 3) Calculate the confidence limits for the population mean at 95 %

Answer 1

Confidence limits for the mean population can be given as,

$CI = \bar x \pm z\dfrac{s}{\sqrt{n}}$

At 95% confidence z = 1.96