StatisticsdrillAddition rule: A or B
A statistics problem from Statisticsdrill. Solve it with one answer box, with a fresh sample on every attempt and the worked steps and spreadsheet function in the answer, and it is checked the moment you submit.
The task
In a survey of adults, 22% buy a coffee, 55% buy a pastry, and 15% do both. If one respondent is picked at random, what is the probability they buy a coffee or buy a pastry (or both)? Round to 4 decimal places.
What this problem teaches
The formula: P(A or B) = P(A) + P(B) - P(A and B).
A hint if you get stuck
P(A or B) = P(A) + P(B) - P(A and B). The overlap is counted twice if you just add.
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