Which side of a tossed coin will land up? Will Flight 742 crash and burn? How many cars will pass a certain point along a highway between 2 p.m. and 3 p.m. on Tuesday? What percentage of a certain array of plutonium atoms will decay in a six-hour period? These questions belong to the realm of probability, because no one can give single answers to them with absolute certainty of correctness.

Salem Press Encyclopedia of Science, 2022. 3p.