141. Solving a chemistry problem

To construct a calibration graph, polarograms of four standard copper (II) solutions were recorded and the wave height hx mm was measured:
cCu * 10 ^ 3, g / ml 0.50 1.00 1.50 2.00
hx, mm 9.0 17.5 26.2 35.0
A sample of brass weighing m 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 was equal to hx:
Option 1
m, g 0.0690
hx, mm 11.0