If you had three groups being tested while using ANCOVA, which of the following choices represents the basic null hypothesis? In this case, consider basic to denote the hypothesis that would be tested in absence of the rejection of the null.
a. Group means for 1, 2, and 3 are not equal.
b. Group means for 1 and 2 are not equal and group means for 2 and 3 are also not equal.
c. Groups 1–3 are equal.
d. Group means for 1 and 2 and group means for 1 and 3 are not equal.
