102. Solving a chemistry problem

1. To construct a calibration curve, 4 standard solutions containing 1.00 were prepared; 1.05; 1.10; 1.15 mg of divalent iron in water complex with ofhenanthroline, the optical density of these solutions is respectively 0.12; 0.36; 0.60; 0.84; The optical density of the test solution measured under the same conditions turned out to be 0.38. Determine the iron content in the solution if it was diluted 5 times before the measurement.