The temperature T on a thermometric scale is defined in terms of property x by the function T = a.ln(xb) , where a and b are constants. The values of x are found to be 1.8 and 6.8 at the ice point and the steam point, the temperatures of which are assigned numbers 0 and 100 respectively. Determine the temperature corresponding to a reading of x = 2.4 on this thermometer.