X2=3.47 . How many degree of freedom correspond to this table?

Degree freedom= (number of columns –1) x (number of rows – 1) =1. IN a 2 x 2 table the degree of freedom, always will be 1.

The result is referrered to the X2 distribution tables and 1 degree of freedom, p-value is 0.1<3.47>0.05.

Do you accept or reject the null hypothesis?

The result is limítrofe. We need the confidence intervals to determine if reject or accept the null hypothesis.