Fisher Exact Probability Test: 2x4
This unit will perform the Freeman-Halton extension of the Fisher exact probability test for a two-rows by four-columns contingency table, providing that the total size of the data set is no greater than N=120. The test will yield two probability values, PA and PB, defined as follows:
PA = the probability of the observed array of cell frequencies plus the sum of the probabilities of all other cell-frequency arrays (such as would be consistent with the observed marginal totals) that are equal to or smaller than the probability of the observed array.
PB = the probability of the observed array of cell frequencies plus the sum of the probabilities of all other cell-frequency arrays (such as would be consistent with the observed marginal totals) that are smaller than the probability of the observed array.
Note that PA and PB are both non-directional (two-tailed) probabilities.

A chi-square test will also be performed on the data set, providing that at least 80% of the cells have an expected frequency of 5 or greater, and that no cell has an expected frequency smaller than 1.0.


Data Entry
C1 C2 C3 C4 Totals


The Fisher test is performed only if N≤120.

Note that PA and PB are both non-directional (two-tailed).





The chi-square test is performed only if at least 80% of the cells have an expected frequency of 5 or greater, and no cell has an expected frequency smaller than 1.0.


R1 
R2 
Totals
Fisher Exact Probability Test
Probability per Definition A:
PA =
Probability per Definition B:
PB =
No. of tables evaluated =
Chi-Square Test (df=3)
Chi-square =
P =


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