Analysis: Use the Blank to set the instrument to zero. Plotthe absorbances of the Sample solutions versus theircontents of lead, in µg/mL, as furnished by the Standardsolution, draw the straight line best fitting the three points,using a linear least-squares fit, and extrapolate the line untilit intercepts the concentration axis on the negative side.From the intercept determine the concentration, C, inµg/mL, of lead in the Sample solution containing 0 mL ofthe Standard solution.Calculate the content, in ppm, of lead in the specimentaken: