Question 1117864: 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 proportion of hybrids gets over 61 miles per gallon?
(b) What proportion of hybrids gets 50 miles per gallon or less? left parenthesis
(c) right parenthesis What proportion of hybrids gets between 59 and 61 miles per gallon?
(d) What is the probability that a randomly selected hybrid gets less than 46 miles per gallon?
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! z=(x-mean)/sd
for a, (61-57)/3.5 or a z of 1.14 Probability z>1,14 is 0.1271.
for b, (50-57)/3.5 is a z < -2. This has a probability of 0.0228
Fob c, z is between (59-57)/3.5 and (61-57)/3.5 or a z between 0.57 and 1.14 with a probability of 0.1572
For d, it is the probability of (46-57)/3.5 or -11/3.5 or z<-3.14 for a probability of 0.0008.
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