To interpret the Χ2 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.
Χ2 can then be determined by looking up the probability value (p)
in a table.