Nick attempted 20 free throws and made 12 of them.
Recall that the experimental probability is given by
[tex]P=\frac{number\: of\: favorable\: outcomes}{total\: number\: of\: outcomes}[/tex]For the given case,
Number of favorable outcomes = 12 (since he made 12 successful throws)
Total number of outcomes = 20 (since he attempted a total of 20 throws)
[tex]P(make\: free\: throw)=\frac{12}{20}=\frac{3}{5}=0.6[/tex]Therefore, there is 3/5 probability that Nick will make a free throw on his next try.