statistics
posted by julide smith on .
For a population of μ = 70 and σ = 20, find the zscore and percentile rank for each of the following X scores: 80, 100, 65, 40.

dont know

z=(xμ)/σ
Find the pvalue of each zscore by looking it up in the z chart.
It'll help you determine the percentile rank if you draw the normal distribution curve.
http://www.mathsisfun.com/data/standardnormaldistributiontable.html 
μ = 70 and σ = 20