Question

Despite what he may have told you, Mr. Robeson is actually quite bad at

making free throws in basketball. On average he makes 35% of the free
throws he takes and he doesn't learn from previous shots. What is the
probability that the first time he makes a free throw is on the 5th shot he
attempts?

Answer 1

0.009754

Explanation:

(.65)^4 x (0.35)

By saying that he makes a free throw on the fifth show, he did not make the first four, therefore 4 of the times he shot, he did not get it in.

If he makes the shot 35% of the time, he doesn't make it 65% of the time: (1-0.35=.65)

On the last shot he made it, which he makes 35% of the time therefore:

You want to multiply : 0.35 (which is = 35%) by itself four times and then multiply that by 0.65 (since the last shot was made)

0.35 x 0.35 x 0.35 x 0.35 x 0.65 = 0.009754 or 0.9754%

There is a 0.9754% chance he makes it BUT a 0.009754 probability