Answer:
78.4% probability at least one does not have a job
Step-by-step explanation:
For each student, there are only two possible outcomes. Either they have a job, or they do not have a job. The probability of a student having a job is independent of other students. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which is the number of different combinations of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
60% of the students at a large university have a job
This means that
Three of these students are randomly selected
This means that
What is the probability at least one does not have a job?
Either all of them have a job, or at least one does not. The sum of the probabilities of these events is decimal 1. So
We want P(X < 3). Then
In which
78.4% probability at least one does not have a job