Detailed description

Tree diagram starting with Probability of cancerĀ  = 0.01 and not having cancer = 0.99. Probability of test being positive given cancer = 0.85. Probability of test being negative given cancer = 0.85. Probability of test being positive given not cancer = 0.07. Probability of test being negative given not cancer = 0.93. Appropriate probabilities are multiplied together to give the result.