Copyright 2007 N Ahbel zscore Copyright 2007 N

Copyright © 2007, N. Ahbel z-score

Copyright © 2007, N. Ahbel z-score • The z-score tells how many standard deviations a value is above or below the mean. • A positive z-score – value is above the mean • A negative z-score – value is below the mean • A z-score of zero – value equals the mean

Recall that… Sample Mean Std. dev. s Copyright © 2007, N. Ahbel Population vs. Sample

Recall that… Sample Mean Std. dev. Population μ s σ Copyright © 2007, N. Ahbel Population vs. Sample

The z-score tells how many standard deviations a value is above or below the mean. The formulae that give z-score are: Sample z-score Copyright © 2007, N. Ahbel z-score

The z-score tells how many standard deviations a value is above or below the mean. The formulae that give z-score are: Sample z-score Population Copyright © 2007, N. Ahbel z-score

Let score = 80 and s = 10. z-score Copyright © 2007, N. Ahbel z-score examples

Let score 90 = 80 and s = 10. z-score Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 +1. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 +1. 0 -1. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 +1. 0 -1. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 +1. 0 -1. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 +1. 0 -1. 0 0. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 +1. 0 -1. 0 0. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 +1. 0 -1. 0 0. 0 +2. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 65 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 65 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 -1. 5 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 65 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 -1. 5 -3. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 65 50 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 -1. 5 -3. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 65 50 95 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 -1. 5 -3. 0 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 65 50 95 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 -1. 5 -3. 0 +1. 5 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 65 50 95 75 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 -1. 5 -3. 0 +1. 5 Copyright © 2007, N. Ahbel z-score examples

Let = 80 and s = 10. score z-score 90 70 80 100 85 65 50 95 75 +1. 0 -1. 0 0. 0 +2. 0 +0. 5 -1. 5 -3. 0 +1. 5 -0. 5 Copyright © 2007, N. Ahbel z-score examples

Copyright © 2007, N. Ahbel z-score