In rare diseases, most "positive" tests are actually false positives, because no medical test is 100% accurate. Enzyme immunoassay tests have a 99.7% probability of a positive result when HIV antibodies are present (sensitivity), and a 98.5% chance of a negative result when no HIV antibodies are present (specicity). The prevalence of HIV/AIDS in the United States is estimated to be 0.60%. If a randomly chosen American is tested for HIV and gets a positive result, what is the chance he or she is really infected? Fill in the missing value: 0.006 x DEW/(0.006 x 0.997 + 0.994 x )