Q4. Use the method of least square to find the coefficients a and b of the straight line (y = ax+b) for the following data Load (kg) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Deflection (mm) 4.4 4.9 6.4 7.3 8.8 10.3 11.7 13.2 14.8 15.3 16.5 17.2 18.9 19.3 1. Show all calculation steps to obtain the result 2. Use Excel to confirm the values of a and b you have obtained by the least square method. a. plot the scattered data b. draw the trendline (built-in Excel and generate the equation) 3. Predict the deflection for the load equal 15 kg