There are 40 students in an elementary statistics claSs. On he baSis of years of experience, the instructor knows that the time needed to grade a randomly chosen first examination paper is a random variable with an expected value of 6 min and a standard deviation of 6 min. a) If grading times are independent and the instructor begins grading at 6:50 pm and grades continously, what is the (approx) probability that he is through graDing before the 11:00 pm TV news begins? b) If the sports report begins at 11:10, what is the probability that he misses part of the report if he waits until grading is done before turning on the TV? (We have to use CLT).