QuestionQuestion 6
In a large population, of the people have been vaccinated. If 5 people are randomly selected, what is the probability that AT LEAST ONE of them has been vaccinated?
Give your answer as a decimal to 4 places.
Studdy Solution
STEP 1
What is this asking?
If we grab 5 random people, what are the chances that *at least one* of them got the vaccine?
Watch out!
"At least one" is not the same as "exactly one"!
It means one *or more*.
STEP 2
1. Find the probability that *none* are vaccinated.
2. Find the probability that *at least one* is vaccinated.
STEP 3
Since of people *are* vaccinated, that means are *not* vaccinated.
So the probability of one random person *not* being vaccinated is , or .
STEP 4
We're picking 5 people.
We want the probability that *none* of them are vaccinated.
Since each person is chosen randomly, the probability of each person not being vaccinated is independent of the others.
So, we can just multiply the individual probabilities together!
STEP 5
The probability that *none* of the 5 people are vaccinated is .
Let's calculate that: .
STEP 6
Remember, there are only two possibilities: either *none* of the people are vaccinated, or *at least one* is.
These two probabilities *must* add up to (or ).
STEP 7
We know the probability that *none* are vaccinated is approximately .
So, the probability that *at least one* is vaccinated is .
STEP 8
The problem asks for 4 decimal places.
Rounding to 4 decimal places gives us .
STEP 9
The probability that at least one person is vaccinated is approximately .
Was this helpful?