Normal Distribution - Concepts

by **Satafternoon** Sat Apr 12, 2008 1:57 pm

This is a concept that I saw in a Princeton Review question.

If scores on a test have a mean of 70 what do you need to find the scores in the 15th percentile?

by **rfernandez** Thu Apr 17, 2008 10:48 pm

Well, you would need to order all of the scores from smallest to largest and you'd have to count how many scores there are, too.

Example:

Suppose there are 30 scores. If you want to know which value represents the 15th percentile, you'd multiply 30 by 15% to get 4.5. Round up to 5.

This means that the fifth smallest score represents the 15th percentile.

Rey