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.
What percent of Sales employees were satisfied?
| Department | Satisfied | Not Satisfied | TOTAL |
|---|---|---|---|
| HR | 12 | 3 | 15 |
| IT | 18 | 6 | 24 |
| Sales | 20 | 10 | 30 |
| TOTAL | 50 | 19 | 69 |
What percent of Sales employees were satisfied?
A poll surveyed voters' party preference.
What percent of voters aged 30–49 preferred Party B?
| Party | 18–29 | 30–49 | 50+ | TOTAL |
|---|---|---|---|---|
| Party A | 40 | 60 | 50 | 150 |
| Party B | 30 | 40 | 30 | 100 |
| TOTAL | 70 | 100 | 80 | 250 |
What percent of voters aged 30–49 preferred Party B?
A media company surveyed viewers on their subscription to a particular streaming service.
What percentage of females in the sample were subscribed?
| Subscription | Male | Female | TOTAL |
|---|---|---|---|
| Subscribed | 70 | 80 | 150 |
| Not Subscribed | 30 | 20 | 50 |
| TOTAL | 100 | 100 | 200 |
What percentage of females in the sample were subscribed?
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