Percentage by mass is the ratio between the mass of the solute and the mass of the solution.
So 3.46g of glucose (solute) by 100g of solution.
First transform 100g of solution into mL using the density:
1.03 g ----- 1 mL
100 g ----- x mL
x = 97.09 mL of solution
Now you have:
3.46 g of glucose ----- 97.09 mL of solution
x g of glucose ---- 54.5 mL
97.09x = 188.57
x = 1.94 g
Answer: 1.94 g of glucose