SOLUTION: A survey finds customers are charged incorrectly for 2 out of every 10 items. Suppose a customer purchases 14 items. Find the probability that the customer is charged incorrectly o

Algebra ->  Probability-and-statistics -> SOLUTION: A survey finds customers are charged incorrectly for 2 out of every 10 items. Suppose a customer purchases 14 items. Find the probability that the customer is charged incorrectly o      Log On


   



Question 1166471: A survey finds customers are charged incorrectly for 2 out of every 10 items. Suppose a customer purchases 14 items. Find the probability that the customer is charged incorrectly on at least 3 items.
In order to achieve this you have to add the binomial probability of 0, 1, 2, 3 together. Yet for some reason I keep turning up wrong... on my 3rd question with 3 attempts each.... I got:
3) .2501388953
2) .2501388953
3) .1539316279
4) .0439804651
=.6982
Please help....

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
At least 3 means NOT 0,1,2
Try that.
Probability is 0.4481 for those, so the answer is the complement or 0.5519