91Ó°ÊÓ

A Cereal brand puts a card with one of five famous NASCAR drivers in each box.

Chance probability$=\frac{1}{5}$

Number of drivers' cards $=5$

Upon drawing two numbers, the variable has a geometric distribution if:

• Two possible outcomes can result from the variable.
• All the results are independent.
• The variables measure the number of draws needed to reach the first success.
• Each drawing has the same chance of being successful.

As we count until the first success (we are interested in five successes), there is no geometric distribution.

Hence, it is not geometric.

Lola picks$=$4 numbers from 1 to 80

Winning numbers from 1 to 80 $=20$

Lola wins money if she picks $=2$or more of the winning numbers

The probability that this happens $=0.259$

Upon drawing two numbers, the variable has a geometric distribution if:

• Two possible outcomes can result from the variable.
• All the results are independent.
• The variables measure the number of draws needed to reach the first success.
• Each drawing has the same chance of being successful.

We measure the number of draws until the first success and$p=0.259$. Since the two outcomes of winning and not winning money are independent, a geometric distribution can be used.

Hence, it is geometric.