075. Solving a chemistry problem

14. To determine silicon in steels in water of the silicon-molybdenum complex, a calibration graph was constructed for pure silicon dioxide. The following values of the optical density of the solutions were obtained:
Dioxide content
silicon, mg/ml 0.02 0.40 0.60 0.80 1.00 1.20
Optical density 0.015 0.29 0.43 0.61 0.74 0.90
A 0.253 g sample of steel was dissolved in acid and, after appropriate treatment, 100 ml of a colored solution of silicomolybdic acid was obtained, the optical density of which was 0.56. Determine the silicon content in steel (in%).