Shaver Manufacturing Inc. offers dental insurance to its employees. A recent study by the Human Resources Director shows the annual cost per employee per year followed the normal distribution, with mean of $1,280 and a standard deviation of $420 per year.

(a) What is the probability that a randomly selected employee will spend more than $1,500 per year on dental expenses?

(b) What is the probability that a randomly selected employee will spend less than or equal to $1,500 per year on dental expenses?

(c) What is the probability that a randomly selected employee will spend between $1,500 and $2,000 per year on dental expenses?