3.49 A corporation was concerned with the basic educational skills of its workers and decided to offer a selected group of them separate classes in reading and practical mathematics. Of these workers, 40%

signed up for the reading classes and 50% for the practical mathematics classes. Of those signing up for the reading classes 30% signed up for the mathematics classes.

a. What is the probability that a randomly selected worker signed up for both classes?

b. What is the probability that a randomly selected worker who signed up for the mathematics classes also signed up for the reading classes?

c. What is the probability that a randomly chosen worker signed up for at least one of these two classes?

d. Are the events “signs up for the reading classes” and “signs up for the mathematics classes” statistically independent?