About 14.3 percent of women who live to 90 develop breast cancer, and of those the test is negative 2 percent of the time. What is the probability of both?

1. Let the probability of developing cancer be 0.143 and the probability of testing negative given cancer be 0.02. 2. The multiplication rule gives the joint probability as 0.143 times 0.02. 3. That product is 0.00286, which rounds to 0.0029. 4. Quoting 0.0200 reports the conditional probability alone and ignores how rare the condition itself is. _Source: OpenStax Introductory Business Statistics (CC BY 4.0), Ch 3 "Probability Topics", section 3.3 Two Basic Rules of Probability_