Question

What is the probability that someone consumed less than 20 gallons of bottled​ water?

Answer 1

The annual per capita consumption of bottled water was 31.9 gallons. Assume that the per capita consumption of bottled water is approximately normally distributed with a mean of 31.9 and a standard deviation of 10 gallons.

What is the probability that someone consumed less than 20 gallons of bottled​ water?

$P(x<20)=P( \frac{x–μ}{\sigma} ​< \frac{20–31.9}{10} ​)=P(z<−1.19)=0.1170$