marblesin the **sample of 3**

It gives you the answer in the question, how many marbles are being chosen is the sample size.

Thanks

Also, how do you tell if something is conditional?

The length of music pieces (in minutes) played daily on Classical FM from 12 noon is a continuous random

variable X with pdf given by

f(x) = 0.025e^(-0.025x), x>=0

0, elsewhere

a. Find the probability, correct to 4 decimal places, that the first piece played on Monday is shorter than 12

minutes.

b. Find the average length of a piece of music on Classical FM.

c. Rachel turns on her radio at a quarter past twelve and hears a familiar tune being played. What is the

probability, correct to 4 decimal places, that she is listening to the first piece played on Monday?

I know how to do part a and b, but how do we know if part c is conditionl or not?

Thanks again