Discrete Variable Standard Deviation Question:

What is the Discrete Variable Standard Deviation for the following numbers: x = 0 and P(X = x) = 0.39 x = 1 and P(X = x) = 0.13 x = 2 and P(X = x) = 0.14 x = 3 and P(X = x) = 0.04 x = 4 and P(X = x) = 0.3