The plaque on the leaning tower of Pisa says that Galileo performed experi - ments there with falling objects. It must be the case that Galileo did indeed perform those experiments there.

inductive; based on signs

Explanation:

From the conclusion of the short passage, it can be seen that the phrase "it must be the case" clearly shows that the person was not too sure or he was inconclusive. However, it is clearly inductive because the conclusion are based on signs, and not facts. Hence we say that this is inductive reasoning and the reason behind it is based on signs.