If the standard deviation were zero, then all men would be exactly 70 inches (177.8 cm) tall. If the standard deviation were 20 inches (50.8 cm), then men would have much more variable heights, with a typical range of about 50–90 inches (127–228.6 cm). The Standard Deviation is a measure of how spread out numbers are. You might like to read this simpler page on Standard Deviation first. But here we explain the formulas. The symbol for Standard Deviation is σ (the Greek letter sigma STDEV function. Excel for Office 365 Excel for Office 365 for Mac Excel for the web Excel 2019 Excel 2016 Excel 2019 for Mac Excel 2013 Excel 2010 Excel 2007 Excel 2016 for Mac Excel for Mac 2011 Excel Starter 2010 More. Less. Estimates standard deviation based on a sample. Calculate the standard deviation of a population. If you're seeing this message, it means we're having trouble loading external resources on our website. If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. Read and learn for free about the following article: Calculating standard deviation step by step If you're seeing this message, it means we're having trouble loading external resources on our website. If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. Standard deviation is a measure of spread of numbers in a set of data from its mean value. Use our online standard deviation calculator to find the mean, variance and arithmetic standard deviation of the given numbers. The divisor in the standard deviation formula is different depending on whether you want the standard deviation for a data set that represents the entire population (divide by the number of data elements minus one), or if your data set is a sample of the population, and you want to calculate the standard deviation to generalize your results to. where x takes on each value in the set, x is the average (statistical mean) of the set of values, and n is the number of values in the set. If your data set is a sample of a population, (rather than an entire population), you should use the slightly modified form of the Standard Deviation, known as the Sample Standard Deviation. The standard deviation of an observation variable is the square root of its variance. Problem. Find the standard deviation of the eruption duration in the data set faithful. Solution. We apply the sd function to compute the standard deviation of eruptions. You and your friends have just measured the heights of your dogs (in millimeters): The heights (at the shoulders) are: 600mm, 470mm, 170mm, 430mm and 300mm. Find out the Mean, the Variance, and the Standard Deviation. And the good thing about the Standard Deviation is that it is useful. Now we can