Answer:
[tex]P(At\ least\ 1) = 0.9963[/tex]
Step-by-step explanation:
Represent the probability that a graduate finds a job with p
[tex]p = 55\%[/tex]
Required
Determine the probability that at least 1 of 7 gets a job.
In probability:
[tex]P(At\ least\ 1) = 1 - P(None)[/tex]
So, we calculate the probability that none of the 7 gets a job.
Represent the probability that a graduate will not get a job with q.
[tex]q= 1 - p[/tex]
[tex]q= 1 - 55\%[/tex]
[tex]q=45\%[/tex]
Represent as decimal
[tex]q = 0.45[/tex]
The probability that none of the 7 will get a job is [tex]q^7[/tex]
i.e.
[tex]P(None) = q^7[/tex]
So, we have:
[tex]P(At\ least\ 1) = 1 - P(None)[/tex]
[tex]P(At\ least\ 1) = 1 - q^7[/tex]
Substitute 0.45 for q
[tex]P(At\ least\ 1) = 1 - 0.45^7[/tex]
[tex]P(At\ least\ 1) = 1 -0.00373669453[/tex]
[tex]P(At\ least\ 1) = 0.99626330547[/tex]
[tex]P(At\ least\ 1) = 0.9963[/tex] -- approximated