3. MPG RATING OF CARS

Suppose that the miles-per-gallon rating of passenger cars is a normally distributed random variable

with a mean of 33.8 mpg and standard deviation of 3.5 mpg.

a) What is the probability that a randomly selected passenger car gets at least 40 mpg.

b) What is the probability that a randomly selected passenger car gets at most 30 mpg.

c) What is the probability that a randomly selected passenger car gets between 30 and 40 mpg.

d) An automobile manufacturer wants to build a new passenger car with an mpg rating that

improves upon 99% of existing cars. What is the minimum mpg that would achieve this goal?

DICK