Question

Suppose 1 in 5 (1/5) JWU students own their own car. If four students are randomly selected, what is the probability that all four own their car?

Answer 1

Answer:

1/625 = 0.0016

Step-by-step explanation:

update, oh sorry, this is about 4 picks and not 5.

so, it is 1/5⁴ = 1/625 = 0.0016

1 in 5 own their own car.

that is 20% or a chance of 1/5 = 0.2 of picking a student owning a car.

let's assume that the total number of students is large enough that each pick does not change the individual probabilities.

each event (picking a student and checking the ownership of a car) is independent and non-overlapping.

so, the probability that all 5 own a car is the chance of picking the 5th student owning a car AND all 4 previous student picks owning a car.

the probability that all 4 previous picks own a car is the chance of picking the fourth student owning a car AND all 3 previous student picks owning a car.

the probability that all 3 previous picks own a car is the chance of picking the third student owning a car AND all 2 previous student picks owning a car.

the probability that all 2 previous picks own a car is the chance of picking the second student owning a car AND the previous student pick owning a car.

the probability that the first student pick owns a car is 1/5 or 0.2

so, we have a clean

1/5×1/5×1/5×1/5×1/5 = 1/5⁵ probability = 1/3125 = 0.00032