Back to Find conditional probability from a model — Problem 3 · Task Set 23
Exercises: Find Conditional Probability as the Fraction of B's Outcomes That Are Also A
Work through each section in order. To find P(A | B), restrict to B's outcomes first, then count how many of them are also in A: the denominator is the number of B's outcomes, NOT all outcomes. Write probabilities as fractions in lowest terms unless asked otherwise, and interpret each conditional probability with a sentence: "among the B's, this fraction are A."
Grade 10·20 problems·~32 min·Common Core Math - HS Statistics and Probability·group·hss-cp-b-6
Work through problems with immediate feedback
A
Warm-Up: Sample Spaces and the Conditional Formula
These problems review ideas you already know from Cluster A.
1.
A standard die is rolled, . Let $B = $ "greater than 3" . By restricting to , how many outcomes are in the new sample space? ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ Of those, how many are even? ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲
number of outcomes in B:
number of those that are even: