Rebecca J. Nash
Statistics
Conditional Probabilities Unit
Day 7
Materials Needed:
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Smart board
Computer attached to projector and smart board
White board set for students (including markers and erasers)
Day 7 PowerPoint
Standards
 HS.S-CP.8 Apply the general Multiplication Rule in a uniform probability model, P(A and
B) = P(A)P(B|A) = P(B)P(A|B), and interpret the answer in terms of the model.
 HS.S-CP.3 Understand the conditional probability of A given B as P(A and B)/P(B), and
interpret independence of A and B as saying that the conditional probability of A given B
is the same as the probability of A, and the conditional probability of B given A is the
same as the probability of B.
 HS.S-CP.5 Recognize and explain the concepts of conditional probability and
independence in everyday language and everyday situations. For example, compare the
chance of having lung cancer if you are a smoker with the chance of being a smoker if
you have lung cancer.
Objectives
 TLW apply conditional probabilities
 TLW construct equations given notation
 TLW utilize new formulas to find the probability of the union
Learning activities
 Intro to today’s work (4 minutes)
o Ask a student to come up and write down the conditional probability formula we
worked with yesterday
 P(A/B) = (P(AB) / P(B))
o Ask a new student to come up and write out how to calculate P(AB) using this
formula
 P(AB) = P(A/B)xP(B)
 Utilize PowerPoint for examples and questions (46 minutes)
o Instructions in the comments for the PowerPoint
o Examples will be done by picking student to diagram each stage on the smart
board (leaving extra space for the next stage of diagramming)
o Questions at the end of the example will be done using white boards and having
students personally display answers
Assessment
 Student whiteboard responses
 Students participation in helping examples
 Formal test on day 10
Reflection