When variance is zero, it implies that all the values are equal. Software like Excel can make this calculation easier. Higher the variance, more heterogeneous is it and smaller the variance, more homogeneous is it. It is calculated by taking the differences between each number in the data set and the mean, then squaring the differences to make them positive, and finally dividing the sum of the squares by the number of values in the data set. In probability theory and statistics, variance is the expected value of the squared deviation from the mean of a random variable. If the CV is negative, the project is over budget and needs corrective. If the CV is positive, the project is under budget, and the progress is good. Actual Cost is the cost spent on the project to date. In statistics, variance measures variability from the average or mean. The formula to calculate SV is below: Cost Variance Earned Value (EV) Actual Cost (AC) The earned value is the value of complete work.

When you measure variance, youre calculating the mean or average of your data points. each value x sample mean n number of values in the sample. Investopedia / Alex Dos Diaz Understanding Variance Here is a simplified version of the variance formula: s2 Y X - x2 divided by (n - 1) where, s2 sample variance Y sum of.