# IJPAM: Volume 91, No. 3 (2014)

AN IMPROVED POISSON TO APPROXIMATE
THE NEGATIVE BINOMIAL DISTRIBUTION

K. Teerapabolarn
Department of Mathematics
Faculty of Science
Burapha University
Chonburi, 20131, THAILAND

Abstract. This paper gives an improved Poisson distribution with mean for approximating the negative binomial distribution with parameters and , where . The improved approximation is more appropriate than the well-known Poisson approximation when is sufficiently large and is sufficiently small.

Received: November 22, 2013

AMS Subject Classification: 62E17, 60F05

Key Words and Phrases: negative binomial probability function, Poisson approximation, Poisson probability function