From the probability distribution, find the standard deviation for the random variable x, which represents the number of cars per household in a town of 1000 households.

x P(x)
0 0.125
1 0.428
2 0.256
3 0.108
4 0.083

Compute the first and second moments. The first moment is the same as the expected value or mean. The second moment is involved in computing the variance.

First moment:

Second moment:

The variance of is

The standard deviation is the square root of the variance:

what am i trying to do? solve?