Assume that each of your calls to a customer service has a p

Assume that each of your calls to a customer service has a probability of 0.6 ofconnecting. Assume that your calls are independent. (Determine the distribution – state theparameter values for that distribution)

(a) What is the probability that your first call that connects is your ninth call?

(b) What is the probability that it requires more than two calls for you to connect?

(c) What is the mean number of calls need

Solution

the distirbution here is geometric distribution.

paramater is p

p=0.6

a) X: number of calls until connection

P(X=9)=(1-p)^x-1*p=(1-0.6)^8*0.6=0.000393

b) P(X>2)=1-P(X<=2)

P(X>2)=1-0.936=0.064

c)E(X)=1/p=1.6667