A resistance R1 is connected in the left gap of a metre bridge and a resistance of 9Ω is connected the right gap in the metre bridge. The null point divides the bridge wire in the ratio 4:3. Now another resistance x Ω is connected in series with R1 in the left gap of te metre bridge and this time the null point divides the bridge wire in the ratio 4:1. Then the value of ‘x’ is