Honors Geometry
Name: ______________________________
REVIEW
Date: _____________
PROBABILITY
Probability is a branch of mathematics that deals with the possibility, or likelihood, that an
event will happen.
Part I. Introduction
Read “Intuitive Idea of Probability” at
http://www.regentsprep.org/Regents/math/ALGEBRA/APR5/LProb.htm and complete the
following notes.
The probability of an event occurring can be expressed as the following ratio:
probability of an event 
The probability of an event happening is between 0 and 1. If an event is impossible, the
probability is zero. If an event is certain, the probability is one. This can be expressed as
a continuum:
0
0.25
0.50
0.75
1.00
Complete the chart above based on the Regentsprep reading.
Part II. Theoretical vs. Empirical Probability
Return to RegentsPrep and read about “Theoretical vs. Empirical Probability” at
http://www.regentsprep.org/Regents/math/ALGEBRA/APR5/theoProp.htm. Define the
following:
Empirical (Experimental)
Probability
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Honors Geometry
Theoretical Probability
Event
Outcomes
Sample Space
ACTIVITY:
Read the first three paragraphs of “Heads or Tails” at
http://utahscience.oremjr.alpine.k12.ut.us/sciber00/7th/genetics/sciber/probab.htm.
With a partner, conduct the coin toss experiment using the “coin toss” simulator at
http://nlvm.usu.edu/en/nav/frames_asid_305_g_3_t_5.html. (open in Safari not Chrome).
Record your data in the chart below.
Number
of tosses
Probability
10
50
100
1. What is the theoretical probability that when a coin is tossed, heads will come up?
2. Using the coin toss simulation you conducted experiments to determine the empirical
probability. What conclusion can you draw from your experiment?
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Honors Geometry
For this activity, use the applet at:
http://www.shodor.org/interactivate/activities/ExpProbability/ (open in
Safari). Roll the dice 10 times and record the tallies in the chart. Repeat 10
more times until you have rolled the dice a total of 100 times.
Find the probability for each of the possible sums when rolling the dice.
Sum
1
2
3
4
5
6
7
8
9
10
11
12
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Frequency
Probability
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Honors Geometry
1) The results from the chart on the previous page are examples of
theoretical or experimental probability? _____________________
2) Complete the chart below with the possible sums when rolling 2 dice.
Dice
1
2
3
4
5
6
1
(1, 1)
(1, 2)
(1, 3)
2
(2, 1)
(2, 2)
3
(3, 1)
4
5
6
3) The results from the above chart are examples of theoretical or
experimental probability? _____________________
4) What sum had the highest theoretical probability? ________
5) What sum had the highest experimental probability?________
6) What factor causes the experimental probability to approach the
theoretical probability?
7) How many elements are in the sample space in the above chart?_______
8) Use the chart on this page to find the following probabilities.
a) P(sum of 3) = _____
b) P(sum of 12) = _____
c) P(sum is even) = _____
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d) P(first # is odd) = _____
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