Question

An eight-sided die has the numbers 1 through 8 on its eight faces. What is 2 points

the expected value when rolling the die? *
O 3.6
04
4.5
06

Answer 1

4.5

Explanation:

(1/8)*1 + (1/8)*2 + (1/8)*3 + ... +(1/8)*8

or

(1/8)*(1 2 + 3 + 4 + 5 + 6 + 7 + 8) = (1/8)*36 = 4.5

We can use a shortcut to sum the numbers 1 through 8. It is given by 8*(8+1)/2.