A formula for the power of the analysis of variance test is derived for the case when the denominator of the $F$ ratio has an even number of degrees of freedom. The form employed is particularly adapted to computation of the power as a function of the alternative hypothesis with arbitrary fixed level of significance and fixed degrees of freedom. For $m$ degrees of freedom in the numerator and 2, 4, 6, 8 and 10 in the denominator, the power functions are deduced from the general formula, with an indication of their use.*