PPT Slide

Suppose you needed to find the percentage BETWEEN two raw scores (two X scores). First find a z for each score. Next, form a picture so you know what you’re looking for. Then, look at Table A, p. 546, to find the percentages you need.

As an example problem, suppose you wanted to find the percentage of scores between 45 and 57, for a distribution whose mean is 50 and standard deviation is 5.

z1 = (45 - 50)/ 5

= -5/5 = -1.00

z2 = (57 - 50)/ 5

= 7/5 = 1.40

Previous slide

Next slide

Back to first slide

View graphic version