Current Electricity Part 3

A wire of length 10‌cm and radius √7×10−4m connected across the right gap of a meter bridge. When a resistance of 4.5Ω is connected on the left gap by using a resistance box, the balance length is found to be at 60‌cm from the left end. If the resistivity of the wire is R×10−7Ωm, then value of R is :