What values can be considered exceptional? For example, in an IQ test, what scores represent the top five percent?
What percentage of values fall below a specific value? In cases where it is impossible to measure every observation of a population, you can estimate the standard deviation using a random sample.Ĭreate a z-score visualization to answer questions like the following: To calculate a z-score you must know the population mean and the population standard deviation. In statistics, the z-score (or standard score) of an observation is the number of standard deviations that it is above or below the population mean.
