Stephen is practicing basketball. He makes a basket from the free-throw line 8 out of 25 shots. What decimal shows the fraction of Stephen’s shots that result in baskets? Billy said that the answer was 3.125. Explain to Billy what he did wrong?

This is a point question, you guys have been quite nice on this app, so I've decided to give out a large amount of coins to those who answer an easy question. Enjoy!