There are two ways to find variance.

The first one: by definition.

Suppose variance =Var(X)

Then var (x) = (2-37/10) 2× (3/5)+(3-37/10) 2× (3/10)+(4-37//kloc-0.

The second type: find according to the formula.

Variance var (x) = e (x2)-[e (x)] 2 = [(2 2× 5/3)+(3 2× 3/10)+(4 2×1/0.

The results of these two algorithms are the same.

I hope you are satisfied.