SOLUTION: The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. What is the probability that a student
Question 471151: The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50. What is the probability that a student uses fewer than 600 minutes? Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!
Hi,
Note: P(z ≥ 2) = .0228 (Table,calculators, etc) Excel: NORMSDIST(-2) = .0228
mean of 500 and a standard deviation of 50
P( x < 600min)
z = (600-500)/50 = 100/50 = 2 Note: P(z ≥ 2) = .0228
P( x < 600) = P(z < 2)= 1 - P(z ≥ 2) = 1 - .0228 = .9772