For hypothesis tests in this section that were two-tailed, we found only the upper critical value. (Recall that for two-tailed tests, the significance level that you look up in the F distribution tables is in fact a/2.) Let's denote that value by FR, where the subscript suggests the critical value for the right tail. The lower critical value FL (for the left tail) can be found as follows: First interchange the degrees of freedom, and then take the reciprocal of the resulting F value found in Table A-5. (FR is often denoted by Fα/2, and FL is often denoted by F1 - a/2.) Find the critical values FL and FR for two-tailed hypothesis tests based on the following values.
a. n1 = 10, n2 = 10, a = 0.05
b. n1 = 10, n2 = 7, a = 0.05
c. n1 = 7, n2 = 10, a = 0.05
d. n1 = 25, n2 = 10, a = 0.02
e. nl = 10, n2 = 25, a = 0.02