P(Positive test|Sufferer) = 98% P(Positive test|healthy) = 10% P(sufferer) = 0.5% P(healthy) = 99.5%

1 Be positive

P(Positive test) = P(Positive Test|Sufferer)P(Sufferer) +`P(Positive Test|healthy)P(healthy) = 0.980.005 + 0.10.995= 0.1044 (10.44%)

2 Correctly diagnose a sufferer of Thripshaw's

P(Sufferer|Positive Test) = P(Positive test|sufferer)P(sufferer)/P(positive test) = 0.980.005/0.1044 = 0.047 (4.7%)

3 Correctly identify a non-sufferer of Thripshaw's

P(healthy|negative test)= P(negative test|healthy)P(healthy)/P(negative test) = (1-0.1)(1-0.005)/(1-0.1044) = 0.9998 (99.98%)

4 Misclassify the person

P(Positive test|healthy)P(negative test|sufferer) = (1-0.1)(1-0.98)= 0.018 (1.8%)