Remember that the formula to calculare KA is the following
Ka = [H+ ion]*[conj. base] / [acid]
Now that you have the data you can do as the following:
Ka = [H+]*[base] / [acid]
Ka = [x]*[x] / [acid - x]
Ka = x^2 / [acid - x]
then we go
Ka = [.032]^2 / [.220 - .032]
Ka = 5.4 x 10^-3.
Or what is the same
Ka = .0054
