Question

Calculate the expected value of the given random variable X. This exercise assumes familiarity with counting arguments and probability. (Round your answer to one decimal place.) X is the number of green marbles that Suzan has in her hand after she selects seven marbles from a bag containing six red marbles and five green ones.

Answer 1

Answer:

The expected value of:

X = 3 green marbles

Step-by-step explanation:

Number of marbles in a bag = 11

Make-up of the bag = 6 red and 5 green marbles

Sussan selects 7 marbles from the bag

The probability of collecting from 5 of the green marbles = 0.45

The probability of collecting from 6 of the red marbles = 0.55

The expected value of X = the probability of selecting a green marble multiplied by the number of marbles selected

= 0.45 x 7

= 3 green marbles