4-19. In a common protein analysis, a dye binds to the protein and the color of the dye changes from brown to blue. The intensity of blue color is proportional to the amount of protein present. Protein (pg): 0.00 9.36 18.72 28.08 37.44 Absorbance: 0.466 0.676 0.883 1.086 1.280 (a) After subtracting the blank absorbance (0.466) from the remaining absorbances, use the method of least squares to determine the equation of the best straight line through these five points (n = 5). Use the standard deviation of the slope and intercept to express the equation in the form y (*s,) = [m (s,)]x + [b (5,)] with a reasonable number of sighi cant figures. (b) Make a graph showing the experimental data and the cal- culated straight line. (c) An unknown gave an observed absorbance of 0.973. Cal- culate the number of micrograms of protein in the unknown, and estimate its uncertainty