1) 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 $81 and $100 and (c) more than 110. 2) use a table of cumulative areas under the normal curve to find the z-score that corresponds to the given cumulative area. If the area is not in the table, use the entry closest to the area. If the area is halfway between two entries, use the z-score halfway between the corresponding z-scores. If convenient, use technology to find the z-score. 3)assume the random variable z is normally distributed with mean u=90 and standard deviation o=4. Find the indicated probability p(x<88)