Q:

A die is rolled 24 independent times. Let Y be the sum of the 24 resulting values. What is the variance of Y?

A die is rolled 24 independent times. Let Y be the sum of the 24 resulting values. What is the variance of Y?
I know how to find the mean of Y, but I'm having some trouble finding the variance of X in order to find the variance of Y. I know Var(y)=24(Var(x)).
Thank you in advance!

A:

Variance is
$$\sum_x\left(x-\mu\right)^2P(x)$$
For a six-sided die, $P(x)$ is always $1/6$, and $\mu=7/2$.
That should get you there.

