- #1
waealu
- 37
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Hi, I have a quick question about variance.
If you are trying to compute Var[3X-Y] where Var[X]=1 and Var[Y]=2,
the correct formula is 32*Var[X] + Var[Y],
but why do you add the variances of x and y?
If you were computing Var[3X+Y] would it also be 32*Var[X] + Var[Y] ?
Thanks, Erik
If you are trying to compute Var[3X-Y] where Var[X]=1 and Var[Y]=2,
the correct formula is 32*Var[X] + Var[Y],
but why do you add the variances of x and y?
If you were computing Var[3X+Y] would it also be 32*Var[X] + Var[Y] ?
Thanks, Erik