Question

What is the variance of X? please help:)?
The following table shows the probability distribution for a discrete random variable.


X 12 15 17 20 22 24 25 30
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 19.59. What is the variance of X? Round your answer to the nearest hundredth.

Answer 1

its a bit long and involved .....

Answer 2

subtract the mean from each X value

square each value you get from that

add up the squares and divide by the number of Xs (if its a population), or one less (if its a sample).

the result is variance