standard deviation standard deviation for sample A standard deviation that is the square root of the quotient of the summation across data points of the square of the distance from each data point to the sample mean, and the degrees of freedom (where the degrees of freedom is sample size minus one). Brian S. Alper, Joanne Dehnbostel, Muhammad Afzal, Khalid Shahin, Kenneth Wilkins Standard deviation is defined as a measure of dispersion that represents the average of the distances from the mean of the dataset to each data point in the dataset. Standard deviation for sample is a standard deviation in which the dataset is a sample. The formula for the standard deviation for sample ( s s) is: s = ∑ n i = 1 ( x i − x ‾ ) 2 n − 1 s= n−1 ∑ n i=1 ​ (x i ​ − x ) 2 ​ ​ where n n is the sample size (the number of independent observations, indexed by i i), x x is observed value, and x ‾ x is the sample mean. The formula to calculate degrees of freedom depends on the model. For the degrees of freedom for a sample standard deviation, given the sample mean, it is n-1, because the nth observation is no longer independent, given the n-1 other observations and the sample mean. ready for release