How To Calculate Mean, Standard Deviation, and Standard Error
When you collect data, the first thing you need to do is analyze it.This usually involves finding the mean, standard deviation, and standard error of the data.This article will show you how to do it.
Step 1: You should get a set of numbers to analyze.
The information is referred to as a sample.The test results for the class of 5 students were 12, 55, 74, 79 and 90.
Step 2: The mean is calculated.
If you divide the numbers by the population size, the mean is X/N.The mean is simply (12+)55+74+79+90)/6.
Step 3: The standard deviation is calculated.
This shows the spread of the population.There is a standard deviation of sq rt.For the example given, the standard deviation is 27.4.If this was a sample standard deviation, you would divide by n-1, the sample size minus 1.
Step 4: The standard error can be calculated.
The population mean is approximated by the sample mean.The closer the sample is to the population mean, the smaller the standard error.If this were a sample of 5 students from a class of 50, the standard deviation would be 17.