6. Variance And Standard Deviation Of D RV

Variance = sum of all possible values minus the mean, squared, times the relative probability.

Ie: (0-3.4)^2 x 0.32 + (1-3.4)^2 x 0.32....

Standard deviation = square root of variance

- denoted with sigma

- represents on average how far off actual values are from the calculated mean.