ESS210B
Prof. Jin-Yi Yu
F- -Distribution
qF-distribution is non-symmetric.
qThere are two critical F values of unequal magnitude.
qWhether to use the upper or the lower critical value depends on the relative magnitudes of S1 and S2:
q     If S1 > S2, then use the upper limit FU to reject the null hypothesis
q     If S1 < S2, then use the lower limit FL to reject the null hypothesis
qOr you can always make S1 > S2 when F is defined. In this case, you can always use the upper limit to examine the hypothesis.
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