1. In a lot of n components, 30% are defective. Two components are drawn at random and tested. Let A be the event that the first component drawn is defective,….

## Identify the distribution of X—name and parameter(s).

1. When local calls are made in NYC, 60% go through on the first try, and the rest get a busy signal. (We assume there is no third possibility).

Let X=# times a call is actually placed for the call to go through

Of course on each try, the call goes through with probability .6.

**a. **Identify the distribution of X—name and parameter(s). Explain your choice. What is

P[X>1].

**b. **How many calls do you ** expect** to have to place in order to get through 5 times? First identify the distribution of the # of calls required to get through 5 different times.

**c. **Let X=total # of calls that get a busy line when 10 different numbers are attempted, once each.

i. What is the distribution of X

ii. What is P[ X >2 ] ?