Question 1

The time is takes for a statistics lecturer to mark final exams is normally distributed, with a mean of12.5 minutes per paper and a standard deviation of 4.3 minutes. There are 40 students in the lecturer's class. What is the probability that she can finish her grading within 8 hours?

Question 2

To reduce absenteeism, a university initiated a program under which staff could participate in a monthly lottery, provided they had perfect attendance and punctuality during the month. A $100 cash prize was awarded to the winner of each monthly lottery. Approximately 80 staff participated in the program. To assess the impact of the program, comparisons were made between sick leave expenditures for eight randomly selected months before and six randomly selected months after the lottery was instituted. Can we conclude, at the 5% significance level, that the mean monthly sick leave expenditure is lower after the institution of the program?

Prior	Post
903	746
812	775
1012	596
855	767
826	469
814	670
755
690