An unidentified material has a yield strength of 75 MPa with…

An unidentified material has a yield strength of 75 MPa with an average grain diameter of 6.25×10-2 mm. At a yield strength of 175 MPa, the same material has an average grain diameter of 6.94×10-3mm. Calculate the yield strength when the average grain diameter is 1.0×10-3 mm.