SOLUTION: The one way commute time is 25.8 minutes. The longest one way travel time is in New York City where the mean time is 38.9 minutes. Assume the distribution of travel times in New Yo

Algebra ->  Probability-and-statistics -> SOLUTION: The one way commute time is 25.8 minutes. The longest one way travel time is in New York City where the mean time is 38.9 minutes. Assume the distribution of travel times in New Yo      Log On


   



Question 1147287: The one way commute time is 25.8 minutes. The longest one way travel time is in New York City where the mean time is 38.9 minutes. Assume the distribution of travel times in New York City follows the normal probability distribution and the standard deviation is 7.9 minutes.
A: What percent are between 30 and 41 minutes?

Answer by amarjeeth123(570) About Me  (Show Source):
You can put this solution on YOUR website!
Mean =38.9
SD=7.9
For a z-distribution we have z=(x-mean)/SD
We have to find the probability that x lies between 30 and 41 minutes.
Plugging in the values,
z1=(30-38.9)/7.9=-1.1265
z2=(41-38.9)/7.9=0.2658
The required probability=0.604812153-0.129959568=0.4748