Suppose the distribution of personal daily water usage in New York City is normally distributed with a mean of 15 gallons and a variance of 25 gallons.Because of a current problem with the distribution of water to its citizens,the mayor wants to give a city tax rebate to the 15 percent of the population who use the least amount of water.What should he use as the water limit for a person to qualify for a city tax rebate?
A)9.825
B)15.00
C)12.20
D)10.25

Question

Quizplus · Accepted Answer

The z-score for the 15th percentile is -1.04. The water limit for a person to qualify for a city tax rebate is the mean plus the z-score times the standard deviation, which is 15 - 1.04 * 5 = 9.825 gallons.

Suppose the Distribution of Personal Daily Water Usage in New