In: Statistics and Probability
Below are the differences between the exponential distribution and the poisson distribution
Exponential Distribution | Poisson Distribution |
It is a continuous distribution with the random variables taking positive real values. | It is a discrete distribution with the random variables taking positive integer values 0, 1, 2,.. |
It deals with the time between occurrences of successive events | It deals with the number of occurrences in a fixed period of time or region. |
The probability distribution with rate parameter is, P(X = x) = exp(-x) |
The probability mass function with rate parameter is, P(X = x) = exp(-) / x! |
Exponential distribution is a memoryless distribution. That is, P(X > a + b | X > a) = P(X > b) holds for exponential distribution |
Poisson distribution is not a memoryless distribution. |
The time interval, between two Poisson events follows exponential distribution. | The number of occurrence of events in a fixed time interval follows Poisson distribution. |