Question

In a survey of 320 customers, 84 say that service is poor.You select two customers without replacement to get moreinformation on their satisfaction. What is the probability that bothsay service is poor?

Answer 1

Step 1

Write an expression for the probability of an event

`\text{Probability of an event = }\frac{required\text{ number of events}}{\text{Total number of possible events}}`

Required number of events = 84

Total number of events = 320

Step 2

Find the probability that both customers selected without replacement say service is poor.

`Pr(customersayserviceispoor)=(84)/(320)`
`Pr(customerselectedwithoutreplacementsayserviceispoor^{}\text{) =}(83)/(319)`

The final answer will be given as

`(84)/(320)*(83)/(319)=(6972)/(102080)=(1743)/(25520)`