ANSWER
0.538
EXPLANATION
The basketball player successfully makes 21 out of 39 free throw attempts.
To find the part of the time that he was successful, we have to divide the total number of attempts by the successful number of attempts that he had.
That is:
[tex]\begin{gathered} \frac{21}{39} \\ \text{Simplifying it by dividing by 3:} \\ \frac{7}{13} \\ \text{Converting to decimal:} \\ 0.538 \end{gathered}[/tex]That is the answer.
