The empirical rule or the 68 95 99 7 rule tells you where most of the values lie in a normal distribution. In sample standard deviation it s divided by the number of data points minus one n 1.
Calculate the mean of your data set.
How to find standard deviation of a sample. Subtract 3 from each of the values 1 2 2 4 6. Calculate the mean average of each data set. Work through each of the steps to find the standard deviation.
Subtract the mean from each of the data values and list the differences. Around 95 of values are within 2 standard deviations of the mean. The mean of the data is 1 2 2 4 6 5 15 5 3.
Around 99 7 of values are within 3 standard deviations of the mean. Sample standard deviation refers to the statistical metric that is used to measure the extent by which a random variable diverges from the mean of the sample and it is calculated by adding the squares of the deviation of each variable from the mean then divide the result by a number of variables minus and then computing the square root in excel of the result. Around 68 of values are within 1 standard deviation of the mean.
How to find standard deviation population here s how you can find population standard deviation by hand.