Use the chart below to answer the following questions. Round your answer to four decimal places. Mammography Screening on 100,000 U.S. Women, Ages 40 to 50 Breast Cancer No Breast Cancer Total Positive Mammogram 720 6,944 7,664 Negative Mammogram 80 92,256 92,336 Total 800 99,200 100,000 a. What is the probability that a woman between ages 40 and 50 has a positive mammogram? b. What is the probability that a woman has breast cancer, given that she has a negative mammogram