SOLUTION: The time taken to install a new telephone is found to be normally distributed with a mean time equal to 60 minutes and a standard deviation of 12 minutes. The probability that the

Algebra ->  Probability-and-statistics -> SOLUTION: The time taken to install a new telephone is found to be normally distributed with a mean time equal to 60 minutes and a standard deviation of 12 minutes. The probability that the       Log On


   

Question 329054: The time taken to install a new telephone is found to be normally distributed with a mean time equal to 60 minutes and a standard deviation of 12 minutes. The probability that the time to install a new telephone will be more than 36 minutes is
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the z score.
z=%28x-mu%29%2Fsigma=%2836-60%29%2F12=-2
P%28-2%29=0.02275
That probability is for values up to x=36 minutes (P%28x%3C=36%29).
P%28x%3C=36%29%2BP%28x%3E36%29=1
P%28x%3E36%29=1-P%28x%3C=36%29
P%28x%3E36%29=1-0.02275=0.97725