5.2 – Some Probability Rules:
Compound Events
• Independent Events: if one outcome does not
affect the outcome of another.
– Replacement
• Dependent Events: the first outcome does
affect the outcome of the next.
– No Replacement
Important Information/Terminology
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•
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•
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Independent:
Dependent:
“and”
“or”
Conditional Probability: P(A, given B occurred)
• Enberg is AWESOME
Multiplication Rules
“AND”
• Multiplication Rule for Independent Events
P(A and B) = P(A) ∙ P(B)
• Multiplication Rule for Dependent Events
P(A and B) = P(A) ∙ P(B, given A has occurred)
*If P(A) = P(A, given B), then the events are independent.
*If P(A) ≠ P(A, given B), then the events are dependent.
Guided Exercise #4 and #5
• As whole group, turn to page 173-174
– Look-over answers
– Whole group clarification
Additional Information
• More than two independent events
• Mutually Exclusive / Disjoint: if they cannot
occur together.
P(A and B) = 0
Addition Rules
“or”
• Addition Rule for Mutually Exclusive Events:
P(A or B) = P(A) + P(B)
• General Addition Rule for Any Events:
P(A or B) = P(A) + P(B) – P(A and B)
Guided Exercise #7 and #8
• As whole group, turn to page 177-178
– Cover answers
– Whole group clarification
Guided Exercise #9
• As whole group, turn to page 180-181
– Cover answers
– Whole group clarification
• Important Summary on P. 181 in orange box
Checkpoint
Compute probabilities of general compound
events
Compute probabilities involving independent
events or mutually exclusive events
Use survey results to compute conditional
probabilities.
Homework
• Read Pages 169-182
– Take notes on what we have not covered
• Do Problems
– Page 182-187 (1-19) odds
• Check odds in back of book
• Read and preload 5.3 information
– Notes/vocab