Answer:
4.04%
Explanation:
Using the Interest rate parity formula according to this theory the forward exchange rate of  should be equal to the spot rate multiplied by the interest rate of the domestic country divided by the interest rate of the foreign country so from this formula
F=S*(1+i)/(1+r)
we derive
(1+r)=F/S*(1+i)
1+r =0.6421/0.6369*(1.032)
1+r =1.0404
 r  = 0.0404/4.04%