Question

what z formula

Answer 1

Z is a function that expresses the mean of anything. For example, Z scores are a way to compare results to a "normal" population. Results of tests or surveys contain thousands of possible results and units; Often these results seem meaningless. For example, knowing that someone weighs 150 pounds may be good information, but if you want to compare it to the weight of a "normal" person, looking at a large table of data can be confusing (especially if some weights are recorded in kilograms). Z-Score can tell you where this person's weight is compared to the population average weight.