I haven't done one of these in years.

But the idea is if they are independent P(AB)=P(A)P(B).

So you obtain the marginal empircal probabilities and see how far we

deviate from that via a goodness of fit test.

I'll do an online search for this.

Yea it's here... http://en.wikipedia.org/wiki/Pearson's_chi-square_test

Look at ...Test of independence

The EXPECTED value in the first cell is

Do that for all your cells and obtain the approximate chi-square test.

The dfs is (3-1)(3-1)=4