The university rule of thumb is that students spend 2 hours outside of class per week for every unit of course credit. for a 4 unit class, this means that students should spend 8 hours a week studying for the course. a random sample of 8 students has been selected and asked how many hours per week they spend on the 4 unit course. the sample values are: {11, 2, 2, 8, 4, 6, 4, 3. }. the sample mean 5=xand the sample standard deviation 10ˆ=a. construct a 95% confidence interval for the population mean number of hours studied per week in this course (assuming the population is normally distributed).b. state and test a null hypothesis that mean study study-time is 8 hours per week. use a 5% significance level and perform a two-sided test. explain why you reject or do not reject your null hypothesis. c. test the same hypothesis as in part b using a one-sided test (again with significance level 5 percent).