THEORETICAL PROBABILITY
Theoretical probability is another way to measure the
likelihood of an event. It represents the chances of an
event occurring in theory, but not necessarily in practice.
theoretical probability = _number of successful outcomes_
total number of possible outcomes
In order to calculate the theoretical probability, all outcomes must be equally
likely. “Equally likely” means each outcome has the same chance of occurring
since the conditions are fair. For example, in the roll of a die, each number has
an equal chance of showing up.
The probability of an event is a value between 0 and 1.
Example 1:
Unit 7 Lesson 2
A standard deck of playing cards has 52 cards, 13 of each suit. If one
card is drawn from the deck, determine the probability of drawing:
a)
a heart
b)
an ace
c)
a heart, club, or jack
d)
a face card
e)
a black diamond
f)
a heart, club, spade,
or diamond
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Example 2:
Two coins are tossed. Use a tree diagram to illustrate all possible
outcomes.
Using the tree diagram, determine the probability of tossing:
Example 3:
a)
only one head
b)
only one tail
c)
two heads
d)
at least one tail
A pair of dice is rolled. Complete the given sum chart.
1
Number
on
Second
Die
Number on First Die
2
3
4
5
6
1
2
3
4
5
6
Calculate the probabilities for the following events:
a)
rolling an even sum
b)
rolling doubles
c)
rolling a sum of 7
d)
rolling a sum other than 7
HOMEWORK:
Unit 7 Lesson 2
p.73–75 #1–9, 11 (T)
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