Personal expressions of probability. The probability associated with a proposition can be used to quantify the confidence in a judgment.

At one extreme, a probability statement of 0 represents the personal belief that the proposition can never happen. At the other extreme, a probability statement of 1 represents the personal belief that the proposition will always occur. Probabilities between these two extremes represent shades of gray. Match each of the following percentages with the narrative statement listed in (a)–

(e) that most closely reflects its meaning.

(a) This seldom happens. It has a very low chance of occurring.

(b) This event is infrequent; it is unlikely.

(c) This happens as often as not; chances are even.

(d) This is very frequent and occurs with high probability.

(e) This event almost always occurs; it has a very high probability of occurrence.