Question

The average number of Saturday night shootings is 5 a night. What’s the chance that there will be a need for exactly 3 shootings this Saturday?

Answer 1

0.14

Explanation:

Using the poisson probability relation :

P(x = x) = (λ^x * e^-λ) ÷ x!

From the question ; mean, λ = 5 ; x = 3

Hence,

P(x = 3) = (5^3 * e^-5) ÷ 3!

P(x = 3) = (125 * 0.0067379) / 6

P(x = 3) = 0.8422375 / 6

P(x = 3) = 0.140