Question

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

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