Question:
The freedom degree (df) number should be 1 or 2? when we analysis the distribution of certain gene's genotypes frequencies between case and control group by Chi2 test. As the following table:
genotype frequency
AA AB BB
case 201 335 45
control 230 321 30
chi-square was 5.25, and the p value=0.0725 given df=2. But the p value will