Standard deviation formula

Standard deviation is a measure that shows how spread out a set of numbers is around their average. To find it, first calculate the average (mean). Then, for each number, find the difference from the mean and square that difference. Next, find the average of these squared differences, which gives the variance. Finally, take the square root of the variance to get the standard deviation. A small standard deviation means the numbers are close to the average, while a large one indicates they are more spread out. It helps understand the consistency or variability in data.