4

Set 2: Probability (Advanced)

Explanation

Answer: C

PROBLEM

In a game, you win $87 with probability 20% and $18 with probability 30%. What is the expected value?

In a game, you win $87 with probability 20% and $18 with probability 30%. What is the expected value?

A.

17.8

B.

45.6

C.

22.8

✓ Correct
D.

27.8

Detailed Explanation

Choice C is the best answer. E = 87(0.2) + 18(0.3) = 17.400000000000002 + 5.3999999999999995 = $22.8

Why others are wrong:
A: 17.8 is incorrect because it does not satisfy the equation.
B: 45.6 is incorrect because it does not satisfy the equation.
D: 27.8 is incorrect because it does not satisfy the equation.