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Stats: ChiSquare Distribution
The chisquare (
) distribution is obtained from the values of the ratio of the sample variance
and population variance multiplied by the degrees of freedom. This occurs when the population
is normally distributed with population variance sigma^2.
Properties of the ChiSquare
•
Chisquare is nonnegative. Is the ratio of two non
negative values, therefore must be nonnegative itself.
•
Chisquare is nonsymmetric.
•
There are many different chisquare distributions, one for each degree of freedom.
•
The degrees of freedom when working with a single population variance is n1.
ChiSquare Probabilities
Since the chisquare distribution isn't symmetric, the method for looking up lefttail values is
different from the method for looking up right tail values.
•
Area to the right  just use the area given.
•
Area to the left  the table requires the area to the right, so subtract the given area from
one and look this area up in the table.
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This note was uploaded on 01/26/2012 for the course MATH 1070 taught by Professor Akbas during the Spring '08 term at Georgia State University, Atlanta.
 Spring '08
 AKBAS
 Statistics, Degrees Of Freedom, Variance

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