**TI89**statsProgram file 05/18/05, 09:27RpoissonZxdebut/Q =-rep srrep zreprep: z%vZrep ;  ;  ; ; :p(- X - )=-sr:p(X > - )=-sr:p(X - )=-sr:p(X < - )=-sr:p(X - )=-sr:p(X = - )=-sr:  U =;  U =?0# ?0# smZ: p(aXb)-p(X>a)-p(Xa)-p(X