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

Variance is the standard deviation squared. Just find the standard deviation: $$st dev = \sqrt{\Sigma(x-xbar)^{2}/(n-1)}$$

anonymous · Answer

i still don't understand what to input into the equation?