the average score on the statistics quiz was a 70, and there was a standard deviation of 10 points. If the z-socre was -1.0 what is the percentile rank?

Question

the average score on the statistics quiz was a 70, and there was a standard deviation of 10 points.  If the z-socre was -1.0 what is the percentile rank?

PsyDAG · Answer

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score. Percentile rank is the proportion below a particular score.

OR…

http://davidmlane.com/hyperstat/z_table.html