The times per week a student uses a lab computer are normallydistributed, with a mean of 6.4 hours and a standard deviation of 1.5 hours. A student is randomly selected. Find the following probabilities.

(a) Find the probability that the student uses a lab computer less than 5 hours per week.

(b) Find the probability that the student uses a lab computer between 7 and 8 hours per week.

(c) Find the probability that the student uses a lab computer more than 10 hours per week.

(a) The probability that a student uses a lab computer less than 5 hours per week is

nothing

.