The following table shows the probability distribution for a discrete random variable.

X 13 16 18 21 23 25 26 31
P(X) 0.07 0.21 0.17 0.25 0.05 0.04 0.13 0.08
The mean of the discrete random variable X is 20.59. What is the variance of X? Round your answer to the nearest hundredth

Question

The following table shows the probability distribution for a discrete random variable.

X	13	16	18	21	23	25	26	31
P(X)	0.07	0.21	0.17	0.25	0.05	0.04	0.13	0.08
The mean of the discrete random variable X is 20.59. What is the variance of X? Round your answer to the nearest hundredth

anonymous · Answer

Find the mean of the distribution and square the difference between each number and the mean and add all the squares together.  Then divide by 8, and your answer is there.

It's annoying, but the concepts is easy :D