Question

A car manufacturer claims that the miles per gallon (mpg) of all its midsize cars can be modeled with a normal model with N(33, 1.70).

1. What proportion of cars have miles per gallon less than 31.2 [P(x ≤ 31.2 mpg)]?
2. What proportion of cars will have miles per gallon greater than 36 [P(x ≥ 36 mpg)]?
3. What proportion of cars will have miles per gallon greater than 29.7 [P(x ≥ 29.7 mpg)]?
4. What proportion of cars will have miles per gallon between 32 and 35 [P(32 mpg ≤ x ≤ 35 mpg)]?
5. How many miles per gallon do the top 10% of the midsize cars have?

Answer 1