Question

The object of a popular carnival game is to roll a ball up an incline

into regions with different values. The probability that Angus will get
30 points in a roll is 30%, 100 points is 55%, and 400 points is 15%.
The expected value, E(X), of a roll is:

Answer 1

Assuming 100% = 1, there is a 0.3 chance of 30 points, 0.55 chance of 100 points, and 0.15 chance of 400 points. Multiplying the chance with the expected values and then adding them up will give you the expected value of one roll.

0.3(30) + 0.55(100) + 0.15(400) = 124
So the expected value of a roll is 124 points