138. Solving a chemistry problem

To determine the content of the acid violet dye in the Rainbow ink, standard solutions were prepared: 0.50 1.00 2.00 3.00 cm3 of a standard dye solution (T = 0.0003) was placed in volumetric flasks with a capacity of 100.0 cm3, brought to distilled water, measured the optical density and obtained the following data:
V, cm3 0.50 1.00 2.00 3.00
A 0.07 0.12 0.23 0.35
A sample of the analyzed ink solution with a volume of 0.004 cm3 was placed on chromatographic paper. After separation into red and violet components, the zone of the acid violet dye was cut out, extracted, diluted in a volumetric flask with a capacity of 50.0 cm3, and the optical density of the resulting solution was measured. Determine the concentration (mg / cm3) of the dye in the test solution if the optical density Ax = 0.19.