Question: 50 The amount of time devoted to studying statistics each week by students who achieve a grade of A in the course is a normally distributed random variable with a mean of 7.5 hours and standard deviation of 2.1 hours.

a) What proportion of A students study for more than 10 hrs per week?

b) Find the probability that an A student spends between 7 and 9 hours studying?

c) What proportion of A students spend less than 3 hours studying?

d) What is the amount of time below which only 5%of all A students spend studying?