SOLUTION: Var (X-Y) = Var (X) + Var (Y)

Question 1134547: Var (X-Y) = Var (X) + Var (Y)

Answer by Glaviolette(140) (Show Source): You can put this solution on YOUR website!
I am not exactly sure what the question is, but you are showing the variance of a difference of two random variables is equal to the sum of the individual variances. Imagine having a pitcher of lemonade. The pitcher holds approximately 60 oz but you are not certain that you made exactly 60 oz so there is some variance there. You pour a glass of lemonade which is about 8 oz, but again, you cannot be certain that you poured exactly 8 oz. So, even though you subtracted out some lemonade from the pitcher, the variance of the amount left increased because you had uncertainty to start and created more uncertainty when you poured the glass.
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