Ex. 1. (Bentley 2.6) A platinum resistance sensor is used to interpolate between the triple point of water (0 °C), the boiling point of water (100 °C) and the freezing point of zinc (419.6 °C). The corresponding resistance values are 100.0 2, 138.5 2 and 253.7 2. The algebraic form of the interpolation equation is: RT = Ro(1+at+BT²); where, R+= resistance at T°C, Ro 2 = resistance at 0 °C, a, B = constants. Find the numerical form of the interpolation equation.