To interpret the X^2 value, first determine the value of the degrees of freedom (df), which is equal to n 1, where n is the number of different categories into which each datum point may fall. The greater the number of categories, the more deviation is expected as a result of chance. For the 3:1 ratio, n = 2, so df = 1. For the 9:3:3:1 ratio, df = 3. X^2 can then be determined by looking up the probability value (p) in a table.