The Poisson Distribution (Edexcel A-Level Further Mathematics): Flashcards

Exponential: continuous (time between events); Poisson: discrete (count)

Time between events

$\lambda = \frac{1}{\mu}$

Rare, constant rate, independent

$\frac{e^{-\lambda} \lambda^x}{x!}$

Discrete

$Po(\lambda_1 + \lambda_2)$

$Po(n\lambda)$

$1 - P(X \leq k)$

$\lambda e^{-\lambda x}$ for $x > 0$