M3.S.CP.C.6.a

Explain the Addition Rule, P(A or B) = P(A) + P(B) – P(A and B) in terms of visual models (Venn diagrams, frequency tables, etc.).

Example Problems
An organization surveyed its employees on satisfaction with a training program.

DepartmentSatisfiedNot SatisfiedTOTAL
HR12315
IT18624
Sales201030
TOTAL501969


What percent of Sales employees were satisfied?
A poll surveyed voters' party preference.

Party18–2930–4950+TOTAL
Party A406050150
Party B304030100
TOTAL7010080250


What percent of voters aged
30–49 preferred Party B?
A media company surveyed viewers on their subscription to a particular streaming service.

SubscriptionMaleFemaleTOTAL
Subscribed7080150
Not Subscribed302050
TOTAL100100200


What percentage of females in the sample were subscribed?
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