Question

Two events are independent if

a. the two events occur at the same time.

b. the probability of one or both events is greater than 1.

c. P(A | B) = P(A) or P(B | A) = P(B).

d. None of these choices are correct.

The newest model of smart car is supposed to get excellent gas mileage. A thorough study showed that gas mileage (measured in miles per gallon) is normally distributed with a mean of 75 miles per gallon and a standard deviation of 10 miles per gallon. What is the probability that, if driven normally, the car will get 100 miles per gallon or better?

a. 2.5%

b. 6%

c. 25%

d. 0.6%

A health conscious student faithfully wears a device that tracks his steps. Suppose that the distribution of the number of steps he takes in a day is normally distributed with a mean of 10,000 and a standard deviation of 1,500 steps. What percent of the days does he exceed 13,000 steps?

a. 97.72%

b. 5%

c. 2.28%

d. 95%

Answer 1