How do you find the standard deviation of a set of values in Excel?

The standard deviation of a set of values in Excel is calculated using the STDEV.P and STDEV.S functions. STDEV.P is used for calculating the standard deviation based on the entire population, while STDEV.S is used for a sample of the population. The distinction is important because populations and samples behave differently statistically.

When using STDEV.P, it treats all the data points as one complete set, while STDEV.S provides a more accurate estimate of standard deviation for a smaller group within a larger population. This functionality makes these functions the appropriate tools for determining how much variation exists in a set of values.

The other options listed do not calculate standard deviation. The VAR function computes variance, which is the square of the standard deviation and thus not directly useful for determining standard deviation without further calculation. The AVERAGE function calculates the mean of a set of values, providing information about central tendency rather than variability. Lastly, the COUNT function simply counts the number of entries in a dataset, which does not relate to standard deviation at all. Therefore, the most accurate and specific choice for finding standard deviation is to utilize the STDEV.P or STDEV.S functions.