Question

A bag contains 4 yellow, 2 red, and 6 green marbles. two marbles are drawn. the first is replaced before the second is drawn. a random variable assigns the number of red marbles to each outcome. calculate the expected value of the random variable.
a. 0.67
c. 0.17
b. 0.56
d. 0.33

Answer 1

Answer:

D. 0.33

Step-by-step explanation:

You multiplied the probability of the marbles by the amount of them and added them up to get your answer. Then convert that answer into a decimal.

Answer 2

Answer:

c. 0.17

Step-by-step explanation:

The bag have 4 + 2 + 6 = 12 balls.

There are 2 red marbles, in 12, the probability to take one red is 2/12. Is important to remember that the first marble was replaced before the second outcome, so the chance for the second is also 2/12:

2/12 = 1/6 = 0.1666 ≈ 0.17