Using Excel to Calculate Poisson Probabilities
You can also conveniently calculate Poisson probabilities using Excel. The built-in POISSON function has the following characteristics:
POISSON(x, m, cumulative)
cumulative = FALSE if you want the probability of exactly x occurrences
cumulative = TRUE if you want the probability of x or fewer occurrences
For instance, Figure 10.2 shows the POISSON function being used to calculate the probability that there will be exactly two accidents in the intersection next month.
POISSON function in Excel for exactly x occurrences.
Cell A1 contains the Excel formula =POISSON(2,1.8,FALSE) ...