



 
Jessica, You found the probability that exactly 2 are defective. They will lose the customer if the number defective is 2 or 3 or 4 or ... or 10. It's easier to calculate the probability that they won't lose the customer. Suppose P(X) is the probability that exactly X of the phones are defective. The probability that they will not lose the customer is then
The probability they will lose the customer is then
Penny  


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