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The case of the random telephone numbers
Author(s) -
Johnston Bruce
Publication year - 1990
Publication title -
canadian journal of statistics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.804
H-Index - 51
eISSN - 1708-945X
pISSN - 0319-5724
DOI - 10.2307/3315421
Subject(s) - telephone number , credit card , numerical digit , order (exchange) , multinomial distribution , mathematics , statistics , arithmetic , computer science , combinatorics , business , finance , world wide web , payment
An unusual pattern of telephone numbers recorded on suspect credit‐card purchases led to the development of a generalized multinomial distribution. One usage of credit cards included 26 telephone numbers with a pattern of 7 unique numbers: 16 of one kind, 4 of another, 2 of another, and 4 different ones. With the assumption that the probability of any digit appearing in a telephone number is 1/10, the pattern of the 26 telephone numbers is found to have a probability of occurrence on the order of 1/10 65 . That is, the chance of such a pattern occurring at random is roughly equivalent to winning nine times in a row the popular ottery, LOTO 6/49.