Let be "x" the number of copies that have been sold to date.
According to the information given in the exercise, 35,300 copies represent 9.9% of the number of copies sold to date.
Then, you can set up the following proportion:
[tex]\frac{35,300}{9.9}=\frac{x}{100}[/tex]
Because "x" represents 100% of the copies sold to date.
Therefore, solving for "x", you get:
[tex]\begin{gathered} (\frac{35,300}{9.9})(100)=x \\ \\ x\approx356,566 \end{gathered}[/tex]
Hence, the answer is:
[tex]356,566\text{ }copies[/tex]
