Two fair dice are thrown, with the scores (X1, X2).

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The discussion focuses on calculating the expected values for two variables derived from rolling two fair dice. The expected value for the sum of the scores (Y = X1 + X2) is determined to be E(Y) = 7, as the average score for one die is 3.5. For the product of the scores (Z = X1 * X2), the expected value is calculated as E(Z) = 12.25, assuming the independence of the dice rolls. The conversation emphasizes the importance of understanding expected values in probability theory.

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Need help with this problem, please!

Two standard, fair dice are thrown, and the scores (X1, X2) are recorded. Find the expected value of each of the following variables:
(a) Y = X1 + X2
(b) Z = X1*X2

I don't even understand what it's asking! :( Any help is appreciated.
 
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Expected value means average. For one die, it is 3.5. For the sum, the averages just add, so E(Y)=7. For the product you need to assume the dice are independent - in which case E(Z)=12.25 (the product).
 
Not sure just providing the correct answer will be enough here. When you say you "don't even understand what it's asking" how much do you know? If I were to ask you the expected value of a single dice roll would you know how to arrive at the answer to such a question?
 

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