The incidence of breast cancer varies depending on a woman's age. the national cancer institute gives the following probabilities for a randomly chosen woman in her 40s who takes a mammography to screen for breast cancer: what percent of women in their 40s taking a screening mammography receive a positive test result? 97%13.96%11.68%2.28%if a randomly chosen woman in her 40s taking the mammography screening test gets a positive test result, the probability that she indeed has breast cancer is the positive predicted value, ppv = p(cancer | positive test). the ppv for this age group is0.8368.0.1632.0.85.0.0268.