Step 1
Write an expression for the probability of an event
[tex]\text{Probability of an event = }\frac{required\text{ number of events}}{\text{Total number of possible events}}[/tex]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.
[tex]Pr(customersselectedsayserviceispoor\text{ ) + pr(}customersselectedwithoutreplacementsayserviceispoor\text{)}[/tex][tex]Pr(customersayserviceispoor)=\frac{84}{320}[/tex][tex]Pr(customerselectedwithoutreplacementsayserviceispoor^{}\text{) =}\frac{83}{319}[/tex]The final answer will be given as
[tex]\frac{84}{320}\times\frac{83}{319}=\frac{6972}{102080}=\frac{1743}{25520}[/tex]