141. Solving a chemistry problem

To determine silver in the alloy by phototurbidimetric titration, a sample of the analyzed metal weighing 3.17 g was dissolved in acid and brought to 100.0 ml with water. 10.0 ml of this solution, 5 ml of gelatin, 5 ml of 0.1 M HNO3 and V ml of KCl solution (T = 0.0080 g / ml) were placed in volumetric flasks with a capacity of 100.0 ml. The optical density of these solutions was:
V (KCl) ml 2.0 4.0 6.0 8.0 10.0 12.0
AND . 0.120 0.330 0.360 0.670 0.680 0.670
Build a titration curve and determine the mass fraction (%) of silver in the alloy.