DSTDEV
DSTDEV estimates the standard deviation of a population, based on a sample of selected entries from the database.
=DSTDEV(database,field,criteria)
The DSTDEV function estimates the deviation of a population based on entries in the list or database. The database in the syntax, shown previously, is the cell reference range or named range of the database, while the field is referenced as the column number from left to right. The criteria is a range that is referenced, and the function operates from the parameters set. The field also can be a cell reference. The standard deviation is actually a standard error amount based on an arithmetic mean formula. To view the actual formula on which the function is based, see the help file.