As a professor I am interested in studying the average marks of all my sections for the 1 quiz. A random sample of 30 students drawn from the population has a mean score of 43 on a scale of 1-50.

Assuming that the population is normally distributed with a variance of 60, what is the confidence interval for the mean value at a 0.05 level of significance.

And based on the confidence level, what conclusion can be drawn regarding the hypothesis that the mean value is different from 40.