Poisson Probability

 
Finding Individual Probabilities (P(X=x))
  1. Let’s suppose that I am trying to find the probability that a X=5 when you have a Poisson (lambda=6.5).
  2. First enter X into a column.
  3. Go to Calc, Probability Distributions, Poisson.
  4. The screen below will appear.
 
  1. Notice that I have entered 6.5 for lambda which is the mean of the Poisson.
  2. If you do not enter a column into the Optional Storage blank, Minitab will display the answer in the session window.
Probability Density Function

Poisson with mu = 6.50000

         x     P( X = x )
      5.00        0.1454
 

Finding the Cumulative Probability
  1. Let’s suppose that I am trying to find the probability that a X<=5 when you have a  Poisson (lambda=6.5).
  2. First enter X into a column.
  3. Go to Calc, Probability Distributions, Poisson.
  4. The screen below will appear.
  1. Notice that I have entered 6.5 for lambda which is the mean of the Poisson.
  2. If you do not enter a column into the Optional Storage blank, Minitab will display the answer in the session window.


Cumulative Distribution Function

Poisson with mu = 6.50000

         x    P( X <= x )
      5.00        0.3690