Chi Squared Tests for Contingency Tables (Edexcel A-Level Further Mathematics): Flashcards

One's occurrence doesn't affect other's probability

$P(A) \times P(B)$

Whether two events are statistically independent

The two events are statistically independent

All entries must be $\geq 5$

Combine columns to eliminate small values

$\frac{(O - E)^2}{E}$

$(rows - 1) \times (columns - 1)$

When $\nu = 1$ (1 degree of freedom)

$\frac{(|O - E| - 0.5)^2}{E}$