VSEM(variable[,filter]) returns the standard error of the mean of a variable. An optional filter can be specified.
The Standard Error of the Mean (SEM) is calculated as follows:
where s is the standard deviation:
This function calculates a statistic on a variable. Be careful when you use this function in cells of the columns that correspond to the variable, because this actually adds a value to the variable which can lead to unexpected and faulty results. You can exclude the cell to avoid this.