(a) The average height of professors at a certain college is 68 inches, and the mean squared deviation(or variance) from this average is 2. X is the height of a randomly chosen professor.

(b) As part of a grand opening promotion, a department store has advertised that every one thousandth purchase made on opening day will be given to the customer for free. The store expects five purchases to be made every minute. X is the time from opening until the first purchase is given away.