Table 3.

Population probabilities under the null hypothesis for two binary random variables. π₁₁ is the probability that a subject will have both Variable 1 and Variable 2 take on the value 1. π₁₀, π₀₁, and π₀₀ are defined similarly.

		Variable 1
		1	0
Variable 2	1	π11	π10	π1+
	0	π01	π00	π0+
		π+1	π+0