Answer to Question #331348 in Statistics and Probability for Jam

Question

INTERVAL ESTIMATE

4. Suppose that the amount of time spend by working student weekly is normally distributed with the standard deviation of 25 minutes. A random sample of 125 observations is drawn and the sample mean is computed as 150 minutes. Determine the 95% confidence interval estimate of the population mean.

Answer 1

$CI=\mu \plusmn z \sigma/\sqrt{n}=150 \plusmn 1.96x25/\sqrt{125}=150 \plusmn 4.38$