The daily water consumption for an Ohio community is normally distributed with a mean consumption of 850,125 gallons and a standard deviation of 64,190 gallons. The community water system will experience a noticeable drop in water pressure when the daily water consumption exceeds 934,672 gallons. What is the probability of experiencing such a drop in water pressure?

Respuesta :

The formula for a z score is
z = (x - µ)/σ
z = (984,000 - 750,000)/80,000 = 2.925
Hence,
p(x > 984,000) = p(z > 2.925) = 1 - p(z ≤ 2.925)
= 1 - 0.9983 = 0.0017