Kati was in the kitchen when she heard a crash. She went into her bedroom and found her window broken and a baseball lying on the ground. Kati said "this baseball broke my window." This statement is an

 inference because she drew a conclusion based on evidence.

why?:

Because the evidence was that she heard the crashing sound, and then when she came into her room saw the broken window and baseball.

It was not an observation because she did not directly see the baseball going through the window