Consider the type of clothes dryer (gas or electric) purchased by each of five d
ID: 3430334 • Letter: C
Question
Consider the type of clothes dryer (gas or electric) purchased
by each of five different customers at a certain
store.
a. If the probability that at most one of these purchases an
electric dryer is .428, what is the probability that at least
two purchase an electric dryer?
I know the answer is A' because that's on chegg, but I want to know why is it A'. If P(A) is the probability that at most 1 electric dry is build, how is P(A') the probability that at least 2 is bought? What is the logic behind this?
(My first Statistics Class)
Explanation / Answer
We have 5 people
Atmost one ---> 0 people or 1 people
Atleast 2 ---> 2 people or 3 or 4 or all 5 people
P(0) + P(1) + P(2) + P(3) + P(4) + P(5) = 1
Now, P(0) + P(1) is P(atmost 1)
And P(2) + P(3) + P(4) + P(5) is P(atleast 2)
Substituting this :
P(atmost 1) + P(atleast 2) = 1
So, P(atmost 1) = 1 - P(atleast 2)
This is how it works out