Thirty percent of all telephones of a certain type are submitted for service while under warranty. Of these, 70% can be repaired, whereas the other 30% must be replaced with new units. If a company purchases ten of these telephones, what is the probability that exactly four will end up being replaced under warranty? (Round your answer to three decimal places.)

The probability that exactly four will end up being replaced under warranty

P(X=4) = 0.20012

Step-by-step explanation:

Explanation:-

by using binomial distribution

P(X=r) =

Given data Thirty percent of all telephones of a certain type are submitted for service while under warranty.

we can take P = 30/100 = 0.3

q = 1-p = 1-0.3 = 0.7

 If a company purchases ten of these telephones that is n= 10

The probability that exactly four will end up being replaced under warranty.

we will use formula

         = 120

on simplification we get P(x=4) = 0.2001

The probability that exactly four will end up being replaced under warranty.

P(x=4) = 0.20012

step-by-step explanation: