The personnel of­fice at a large electronics fi­rm regularly schedules job interviews and maintains records of the interviews. From the past records, they have found that the length of a fi­rst interview is normally distributed, with mean μ = 35 minutes and standard deviation σ = 7 minutes.

(a) What is the probability that a fi­rst interview will last 40 minutes or longer?

(b) Nine fi­rst interviews are usually scheduled per day. What is the probability that the average length of time for the nine interviews will be 40 minutes or longer?