Unformatted text preview: egion of the curve gives us
The
the relative frequency or the “probability” that a
score falls inside that region.
score Normal Distributions
Normal Properties: 1) They are continuous over the interval (∞, ∞) 2) They are Bell Shaped 3) They are Symmetrical 4) The Points of Inflection of the curve are each located
4)
at μ ± σ. 5) They are unimodal. Normal Distributions
Normal Normal distributions are important because many (but
Normal
not all) real world things can be modeled by normal
distributions.
distributions. Examples:
Examples: Scores on tests taken by many people (SAT, ACT, AP, etc..) IQ scores Characteristics of homogeneous biological populations Yields of crops Heights of women Lengths of cockroaches Therefore if you know something follows a normal
Therefore distribution, you know two things without any work
distribution, Notation:
Notation: The mean, μ, and standard deviation, σ,
The
and
completely specify a normal distribution. We
use the following notation:
use N ( μ, σ ) Normal Curves differ amongst each other based
Normal
on the specified mean and standard deviation.
on 1. Shape: symme...
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 Winter '13
 Jessell
 Empirical Rule, Normal Distribution, Standard Deviation, normal distributions, Bell shaped

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