Each worksheet states the sample-space assumptions, distribution support, and counting convention needed for the selected model. Probability tables stay fully labeled, and Bayes questions identify the conditioning event before reversing it.
Learning objective
What this activity builds
Use exhaustive disjoint branches to find a total event probability, then reverse the conditioning correctly with Bayes' theorem.
Worked example
Sources A and B supply 40% and 60% of items; their pass rates are 80% and 90%. Find P(A | pass).
0.40(0.80) / [0.40(0.80)+0.60(0.90)] = 0.372.
The denominator is the total pass probability across both disjoint sources.
Teaching notes
Make the practice count
Label priors before conditional rates.
Compute the total conditioning-event probability before the Bayes numerator.
Check that posterior probabilities stay between 0 and 1.
Make it yours
Customize the practice
Choose your options, update the preview, then download the exact same pages.
Choose two- or three-source partitions, forward or reverse probability, final precision, and question count.