Problema Solution
In the past year 14% of businesses have eliminated jobs. If 5 businesses are selected at random , find the probability that at least 3 have eliminated jobs during the last year.
Answer provided by our tutors
The probability of x successes in n trials is:
P = nCx* p^x *q^(n-x) where p and q are the probabilities of success and failure respectively.
In this case p = .14 , q = .86 and n = 5
nCx =n!/(x!(nix)!)
P(at least 3 of the five eliminated jobs) = 1 - P(0) -P(1) -P(2)
P(0) = (.87)^5 = .4984
P(1) = 5*(.13)^1(.87)^4 = .3724
P(2) = 10*(.13)^2(.87)^3 = .1113
P(at least 3 of the five eliminated jobs) = 1 - .9821 = .0179