27. Solving a chemistry problem

4. To construct a calibration graph, we recorded polarograms of four standard solutions of copper (II) and measured the wave height hx mm:
Ссu*103, g/ml 0.50 1.00 1.50 2.00
hx, mm 9.0 17.5 26.2 35.0
A weighed portion of brass weighing t g was dissolved and the solution was diluted to 50.00 ml.
Calculate the mass fraction (%) of copper in the analyzed samples if the wave height on the polarograms turned out to be equal to hx:
Option 1
t, g 0.0690
hx, mm 11.0
Answer: 1) 44.93%.