Chapter 4-2: Fundamentals of Probability

Assignments and due dates for each chapter are announced in class. Typical problems include:

4-2 page 146

2 to 24, even numbered problems

The Sample Space is the list of all possible unique events.

In the case of flipping a single fair coin three times, the list of 8 unique events is shown in the table below.

Sample space
Flip a single coin three times
Event	1^st flip	2^nd flip	3^rd flip	# of heads
1	H	H	H	3
2	H	H	T	2
3	H	T	H	2
4	H	T	T	1
5	T	H	H	2
6	T	H	T	1
7	T	T	H	1
8	T	T	T	0

Probability is always the number of ways a particular outcome can happen divided by the number of all possible outcomes.

While the probability of any of the 8 events listed is 1/8 or 12.5%, the probability of getting 2 heads is 3/8 or 37.5% because there are 3 ways to get 2 heads.
The complete relative frequency table is listed below.

Distribution
Flip a coin 3 times
Event	# of heads	Frequency	Relative Frequency
1	0	1	1 ÷ 8 = 12.5%
2	1	3	3 ÷ 8 = 37.5%
3	2	3	3 ÷ 8 = 37.5%
4	3	1	1 ÷ 8 = 12.5%
	Sums »	8	8 ÷ 8 = 100.0%