Problem 3 (MATLAB): The following data are provided: 0.4 0.8 1.2 1.6 2.0 2.3 1. Use least square regression to fit the data with straight line. That is, find out the values for a and b for y- a +bx 2. Use least square regression to fit the data with exponential equation y ae 3. Fit the data with parabola y ab+c. 4. Plot the original data and the three obtained fitting curves on the same figure. 5. Find out the norm of residual, as well as the coefficient of determination () for each of the above regression methods. Discuss which fitting can describe the data in a best way