what does degrees of freedom tell you 
degrees of freedom tell you how many units within a set can be selected without constraints to still abide by a given rule overseeing the set for example consider a set of five items that add to an average value of 20 degrees of freedom tell you how many of the items 4 can be randomly selected before constraints must be put in place in this example once the first four items are picked you no longer have the liberty to randomly select a data point because you must force balance to the given average 