x,mean,cumulative!This function is available for compatibility with Excel 2008 and earlier.Returns the Poisson distribution!is ...

!x,mean,cumulative!!This function is available for compatibility with Excel 2008 and earlier.Returns the Poisson distribution!is the number of events!is the expected numeric value, a positive number!is a logical value: for the cumulative Poisson probability, use TRUE; for the Poisson probability mass function, use FALSE!