SOLUTION: The mean gas mileage for a hybrid car is 57 miles per gallon. Suppose that the gasoline mileage is approximately normally distributed with a standard deviation of 3.5 miles per gal

Algebra ->  Probability-and-statistics -> SOLUTION: The mean gas mileage for a hybrid car is 57 miles per gallon. Suppose that the gasoline mileage is approximately normally distributed with a standard deviation of 3.5 miles per gal      Log On


   

Question 946898: The mean gas mileage for a hybrid car is 57 miles per gallon. Suppose that the gasoline mileage is approximately normally distributed with a standard deviation of 3.5 miles per gallon.
A. What is the probability that a randomly selected hybrid gets more that 61 miles per gallon? 0.127
B. What is the probability that a randomly selected hybrid gets 52 miles per gallon or less?
C. What is the probability that a randomly selected hybrid gets between 58 and 61 miles per gallon? 0.261
D. What is the probability that a randomly selected hybrid gets less than 45 miles per gallon?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find the z score for each scenario, then use the normal distribution function.
z=%28x-mu%29%2Fsigma=%28x-57%29%2F3.5
a) z=%2861-57%29%2F3.5=1.143
0.8735, so then it's 1-0.8735=0.127 for greater than 61.
b) z=%2852-57%29%2F3.5=-1.429 so then P=0.0766
c) z%5B1%5D=%2858-57%29%2F3.5=0.286 and z%5B2%5D=%2861-57%29%2F3.5=1.143
So then P=.873451-.612452=0.261
d) z=%2845-57%29%2F3.5=-3.429 so then P=0.0003