Question

Use the following information for
The probability that a randomly selected cereal box has a prize is 0.2. Suppose you purchase box after box until you have found 2 of these prizes.
What type of probability distribution best describes this problem?

Answer 1

Answer:

Negative binomial distribution

Step-by-step explanation:

The negative binomial distribution is the one which best describes this problem.

This probability measures the probability of needing X trials to obtain r sucesses with p probability.

The mean value is given by

$E(X) = \frac{r}{p}$

Here, for example, we want 2 sucesses with 0.2 probability. So $r = 2, p = 0.2$

$E(X) = \frac{r}{p} = \frac{2}{0.2} = 10$