Exercise 21 Page 798

The event of the first chip chosen being yellow affects the probability of the second one not being blue because there is one fewer chip from which to choose, and one fewer non-blue chip to choose. Therefore, the events are dependent.

Probability of Dependent Events

If two events, $A$ and $B,$ are dependent, then the probability of both occurring is the product of the probability of $A$ and the probability of $B$ after $A$ occurs. $$\begin{array}{c}P(A\text{ and }B)=P(A)\cdot P(B\text{ following }A)\end{array}$$

Let's start by calling the event of choosing a yellow chip from the bowl $A$ and calculating its probability. The bowl contains $30$ chips, $12$ of which are yellow.