Find the sample mean: add all values and divide by the number of values, ( bar{x} = frac{sum x_i}{n} )
Subtract the mean from each value to get each deviation: ( x_i – bar{x} )
Square each deviation: ( (x_i – bar{x})^2 )
Add all squared deviations: ( sum (x_i – bar{x})^2 )
Divide by ( n – 1 ) to get the sample variance: ( s^2 = frac{sum (x_i – bar{x})^2}{n – 1} )
Take the square root of the sample variance: ( s = sqrt{s^2} )