Q1) In 1982, CDC report explained that 3 persons who had before received whole blood transfusions developed acquired immuno deficiency syndrome (AIDS). In 1948, after discorvery of human Immuno deficiency virus (HIV), 5 companies were licensed to produce enzyme- linked immunos orbent assay(EIA, then called ELISA) test. Kits for detecting HIV antibody. In march, 1985, first kit was approved by FDA. Numerous complex issues were explained even before licensure such as false positive test results to find out whether test- positive blood donors must  be notified. It is now march2, 1985. First HIV antibody test kits will arrive in blood banks in state in few hours, meeting with state Epidemiologist to explain suitable use of this test are commissioner of health , medical director of regional blood bank, and chief of state drug abuse commissioner.

To help discussion, state epidemiologist turns to pre licensure information regarding sensitivity and specificity of test kit A. Information points out that sensitivity of test kit a is 95% and specificity is 98%.

With this information, by constructing a 2 by 2 table, compute the predicative value positive and predictive value negative of the ELA (sensitivity of test kit a is 95% and specificity is 98%.) in hypothetical population of 1000000 blood donors. Suppose that actual prevalence of HIV antibody among blood donors Is 0.04%