Exponential Distribution Formula

The exponential distribution in probability is the probability distribution that describes the time between events in a Poisson process.

Probability Density Function

f(x;λ)={λe−λxx≥00x<0

Cumulative Distribution Function

F(x;λ)={1–e−λxx>=0,0x<0.

where

λ>0
is called the rate of the distribution.

The mean of the Exponential (

λ
) Distribution is calculated using integration by parts as –

E[X]=∫−∞∞xfX(x)dx=λ∫0∞xe−λxdx=λ{[x∫e−λxdx]0∞−[∫ddxx(∫e−λxdx)dx]0∞

Simplifying further,

=λ{[xe−λx−λ]0∞−[∫e−λx−λdx]0∞}=[−xeλx]0∞+[∫e−λxdx]0∞=[−xeλx]0∞+[e−λx−λ]0∞=[0−0]−1λ[0−1]=1λ

 

Comments

Leave a Comment

Your Mobile number and Email id will not be published.

*

*