In: Statistics and Probability
Draw a probability tree diagram for the following experiment: Suppose there are five balls in an urn. Three are red and two are blue. We will select a ball, note the color, and, without replacing the first ball, select a second ball. What is the sample space of this
experiment? What is the associated probability distribution in this
experiment?
Let R : event of selecting red ball
B : event of selecting blue ball
Sample Space : RB RR BB BR
Finding probabilities for each item in sample space
P(RB) = P(select first red ball x select second blue ball)
(2nd ball is without replacing the first ball, hence denominator is 4)
(Second fraction 2/4 is for the second red ball. as total red balls reduce from 3 to 2
before drawing the second ball)
Probability Distribution
Sample Space | RB | RR | BB | BR |
Probability | 0.3 | 0.3 | 0.1 | 0.3 |
Probability Tree Diagram