In a large set of data, the frequency of the occurrence of the first digit of the numbers in the set is not evenly distributed. The number 1 turns up as the first digit about 30% of the time, more often than any other.
Dr. Benford derived a formula to explain this. If absolute certainty is defined as 1 and absolute impossibility as 0, then the probability of any number “d” from 1 through 9 being the first digit is log to the base 10 of (1 + 1/d). This formula predicts the frequencies of numbers found in many categories of statistics.
This law is being used to catch fradulent activity of all kinds. Read more at Rex Swain’s Home Page