Question

The cost of all maintenance for specific type of car during its 1st year is exponentially distributed with a mean of $160. What is the probability that a randomly selected car of this type requires more than $320 in maintenance during its 1st year?

Answer 1

Solution:

We are given

λ = 1/160

We have to find P(X>320)

P(X>320) = 1 – P(X<320)

P(X≤x) = 1 – exp(-λx)

P(X<320) = 1 - exp(-320/160)

P(X<320) = 0.864665

P(X>320) = 1 – P(X<320)

P(X>320) = 1 – 0.864665

P(X>320) = 0.135335

Required probability = 0.135335