The monthly utility bills in a city are normally distributed, with a mean of $100 and a standard deviation of $15. Find the probability that a randomly selected utility bill is (a) less than $68, (b) between $85 and $120, and (c) more than $150 (a) The probability that a randomly selected utility bill is less than $68 is (Round to four decimal places as needed.) (b) The probability that a randomly selected utility bill is between $85 and $120 is (Round to four decimal places as needed.) (c) The probability that a randomly selected utility bill is more than $150 is (Round to four decimal places as needed.)