The Poisson distribution is one of the most commonly used distributions in statistics.
This calculator finds Poisson probabilities associated with a provided Poisson mean and a value for a random variable.
P(X = 3): 0.14037
P(X < 3): 0.12465
P(X ≤ 3): 0.26503
P(X > 3): 0.73497
P(X ≥ 3): 0.87535
Thank you.
Question concerning Poison
I am curious about small averages and large averages and irregular events.
First I experimented with a small average. After 470 events I came up with an answer of .538. I wanted to know how may times a zero came up. According to Poisson I should have 58.391 percent should have been zeroes. i ended up with 53%. It seems in to me after 470 events I I should have been a closer to 58 than 53. So my first question is: Does Poisson not work on small averages?
I next tried a large average of 285 I got an answer of NaN. So I assume Poisson does not work for large averages. Is this true?
Finally the third thing I am curious about is irregular X. I see quite often on the internet an example of phone calls to a call center. My theoretical scenario is The average for one particular 8 hour day is 1000. But between 8&9 there is 10 calls. Between 12 noon and 1 there is 700 calls. Each hour has a different amount of calls the rest fill of the hours fill out to average 1000. Each day these totals vary. So the question is, does Poisson work or not work with irregular random events?
Thanks for your time,
Roddy Clack