Use a ?2 test to test the claim that in the given contingency table, the row variable and the column variable are

independent.

Tests for adverse reactions to a new drug yielded the results given in the table. At the 0.05

significance level, test the claim that the treatment is independent of the

reaction (whether or not headaches were experienced).

Drug Placebo

Headaches 11 7

No headaches 73 91