Download Chi-square or X 2

yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Central limit theorem wikipedia, lookup

Concerned with testing:
Two factors: Test of Independence
Whether or not a set of data fits a
particular distribution: Goodness-ofFit Test
Chi-square or X 2
Continuous distribution
Generally, skewed to the right (long right tail)
Shape changes when the dfs change (df =
degrees of freedom and depends on the sample
size) df = 2
df = 24
Chi-square or X 2
When the dfs are 90 or more, the chi-square
curve and normal curve are almost the same.
Mean and Standard Deviation
μ = the # of dfs
σ = √2(# of dfs)
Example: For a chi-square distribution
with df = 45,
μ = 45
σ = √2(45) = 9.4868