1. Odds of Having Cancer

2. Test Results Positive Negative Total Yes 9 1 10 Cancer No 99 891 990

3. Your chance of cancer = 9/108 = 8.3%
Test Results
Positive Negative Total
Yes
Cancer No
Total
Your chance of cancer = 9/108
= 8.3%

4. Retest Results Positive Negative Total Yes 8 1 9 Cancer No 10 89 99

5. Your chance of cancer = 8/18 = 44.4%
Retest Results
Positive Negative Total
Yes
Cancer No
Total
Your chance of cancer = 8/18
= 44.4%