Determining standard Deviation(Risk Measure) =V∑(R1-R)2(P1) Standard Deviation, o is a statistical measure of the variability of a distribution around its mean It is the square root of variance. 5-75-7 Determining Standard Deviation (Risk Measure)  =  ( Ri - R ) 2 ( Pi ) Standard Deviation, , is a statistical measure of the variability of a distribution around its mean. It is the square root of variance. n i=1