Contingency tables - test for independence

Calculator (TI-82) help for calculation of the test statistic.

(This works for the TI-83/84 also, but that calculator has its own, better technique using matrices.
See your text book)

EXAMPLE:
 

	embezzlement	fraud	forgery
sent to jail	22 (33.97)	130 (118.68)	20 (19.35	172
not sent to jail	57 (45.03	146 (157.32)	25 (25.65)	228
	79	276	45	400

1. Put the observed values in list L1.

2. Put the expected values in list L2. These are the values in the table in parentheses. The calculation

  for the expected values is E = (row total)(column total)/(grand total).

3. Calculate the test statistic (chi - square) as follows:

  sum((L1 - L2)^2/L2)

  where "sum" is found in 2nd List MATH menu

4. The test statistic for the above example is:

  (chi-square) = 9.3323