More than Two Categories (2 of 3)

---

	Frequency
Better	45 (33.333)
Worse	25 (33.333)
Same	30 (33.333)
Total	100

The chi square statistic is then computed using the formula:



The degrees of freedom are equal to the the number of categories -1. For this example,



Since there are three categories, the degrees of freedom equal 3 - 1 = 2. From a chi square table, it can be determined that the probability value is 0.039. Therefore, the null hypothesis of one third better, one third worse, one third the same can be rejected.