The Probability Scale from 0 to 1

Look at the probability line drawn from 0 to 1. The left end is 0 (impossible) and the right end is 1 (certain). The middle, 1/2 or 0.5, is even chance. Words sit along the line: impossible, unlikely, even chance, likely, certain. The number always lies between 0 and 1, and never goes outside that range.