IB skill practice

Use total probability

Calculate a total probability across mutually exclusive pathways.

Paper 1, Paper 2 5 marks Difficulty 4

Use total probability - exam scenario

For a retail analyst, \(P(A)=0.39\), \(P(B|A)=0.68\), and \(P(B|A')=0.2\). Calculate \(P(B)\). Enter the requested value and choose the interpretation that matches the result.

Worked practice: result and interpretation

Calculate the requested result first, then choose the interpretation that follows from it.