Question

The annual per capita consumption of bottled water was 32.6 gallons. Assume that the per capita consumption of bottled water is approximately normally distributed with a mean of 32.6 and a standard deviation of 12 gallons. The probability that someone consumed more than 33 gallons of bottled water is?

Answer 1

0.4867

Explanation:

Given an approximately normal distribution:

Z = (x - mean) / standard deviation

Mean = 32.6 ; Standard deviation = 12

For :

P(x > 33)

Z = (33 - 32.6) / 12

Z = 0.4 / 12

Z = 0.0333

Hence, using the Z distribution table :

P(Z > 0.0333) = 1 - P(Z < 0.333)

P(Z > 0.0333) = 1 - 0.51328

P(Z > 0.0333) = 0.48672