Thread: Basic Probability Help!!

Hi im having trouble with this question.
If anyone could help me out thatd be great , Im not sure where to start!


Heres info:

The cost of a phone call passed on to a 'live' operator is approx. ten times that of a call answered by an automated customer-service system.However , as more and more companies have implemented automated-systems, customer annoyance with these sytems have grown.Many customers are quick to leave the automatedsystem when given an option such as ''press 0 to talk to a live operator" . Research has shown that approxiamtely 40% of all callers to automated systems will automatically opt to go to a live operator when given the chance.

And questions:


1)What is the probability that, from a total of 10 callers, none will automatically opt to talk to a live operator?




2)What is the probability that , from a total of ten callers, at least 5 will automatically opt to talk to a live operator?




3)What assumptions are necessary for the validity of the two above answers?



so far what ive come up with is :

1) 0.6
2)0.4
3) That all calls are made to same company , that customers arnt fussed about price?


Please Help!!!

Originally Posted by Lucy1

Hi im having trouble with this question.
If anyone could help me out thatd be great , Im not sure where to start!


Heres info:

The cost of a phone call passed on to a 'live' operator is approx. ten times that of a call answered by an automated customer-service system.However , as more and more companies have implemented automated-systems, customer annoyance with these sytems have grown.Many customers are quick to leave the automatedsystem when given an option such as ''press 0 to talk to a live operator" . Research has shown that approxiamtely 40% of all callers to automated systems will automatically opt to go to a live operator when given the chance.

And questions:


1)What is the probability that, from a total of 10 callers, none will automatically opt to talk to a live operator?




2)What is the probability that , from a total of ten callers, at least 5 will automatically opt to talk to a live operator?




3)What assumptions are necessary for the validity of the two above answers?



so far what ive come up with is :

1) 0.6
2)0.4
3) That all calls are made to same company , that customers arnt fussed about price?


Please Help!!!

Let X be the random variable number of callers that opt to talk to a live operator.

X ~ Binomial(n = 10, p = 0.4).

a) Find Pr(X = 0). Your answer is wrong.

b) Find Pr(X > 4). Your answer is wrong.

c) What criteria must be satisfied for X to have a binomial distribution? Some of what you say is correct and follows from the criteria ......