SOLUTION: What is the expected value of rolling a fair six-sided cube, with faces numbered 1 through 6, one time? a. 1 b. 3 c. 3.5 d. 6

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Question 1180804: What is the expected value of rolling a fair six-sided cube, with faces numbered 1 through 6, one time?
a. 1
b. 3
c. 3.5
d. 6
Answer by MathLover1(20849) About Me  (Show Source):
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Let X be the random variable representing the result of the die roll. Recall that a die roll has the following outcomes:
1 2 +3+ 4 5 6
Since the die is fair, each of these outcomes has a probability of 1%2F6.
The expected value is then the sum

E%5BX%5D=1%2F6%2B1%2F3%2B1%2F2%2B2%2F3%2B5%2F6%2B1
E%5BX%5D=7%2F2
E%5BX%5D=3.5

answer: c. 3.5