SOLUTION: a company finds that 85% of their invoices are paid on time and 15% are not. If a random sample of 9 invoices is checked, find the probability that exactly seven will be paid on ti

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Question 871232: a company finds that 85% of their invoices are paid on time and 15% are not. If a random sample of 9 invoices is checked, find the probability that exactly seven will be paid on time and fewer than 2 invoices will not be paid on time
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

p(not on time) = .15,  n = 9

P(x < 2) =  1 - P(x ≥ 2) = .5995     |P(x ≥ 2)= 1 - binomcdf(9, .15, 1) = .4005

P(x = 7 on time) = binompdf(9, .85, 7) = .2597  0r 25.97%