11.20 Find the incorrectly used symbol or symbols in each of the following statements or formulas. For each statement or formula, (i) state which symbol(s) is/are used incorrectly, (ii) explain why the symbol(s) in the original statement is/are incorrect, and (iii) state which symbol(s) should be used.

a. When calculating an F statistic, the numerator includes the estimate for the between-groups variance, s.

b. SSbetween = (X − GM) 2