1. Distribution Model
A smooth representation of the distribution of ALL individuals in the POPULATION. -3 -2 -1 1 2 3 4
Quantitative Value 10 20 30 40 50
Frequency
Normal Distributions

2. Distribution Model
Useful for estimating the proportion of individuals within a particular range of values (e.g., X < -1). -3 -2 -1 1 2 3 4
Quantitative Value 10 20 30 40 50
Frequency
Normal Distributions

3. s m Normal Distribution Most important distribution model
Infinite number, but each is …
bell-shaped
centered on m
dispersion of s
x ~ N(m,s) s m
Quantitative Value
Normal Distributions

4. N(m,s) s m m-s m+s m-3s m-2s m+2s m+3s Quantitative Value
Normal Distributions

5. N(10,4) 4 -2 2 6 10 14 18 22
Quantitative Value
Normal Distributions

6. N(0,1) 1 -3 -2 -1 1 2 3
Quantitative Value
Normal Distributions

7. N(10,4) -2 2 6 10 14 18 22
Quantitative Value
Normal Distributions