The faculty and staff at Dana-Farber Cancer Institute in Boston are required to undergo a tuberculosis test each year. Use the following table to answer each question.
TEST RESULTS
POSITIVE: TB= 4995, NO TB= 99, 950, TOTAL= 104,945
NEGATIVE: TB= 5, NO TB= 9, 895, 050, TOTAL= 9, 895, 055
TOTAL: TB= 5000, NO TB= 9,995,000, TOTAL= 10, 000,000
a.) If Dana-Farber faculty or staff worker goes in for a TB test, what is the chance of him/her getting a postive test result?
b.) What is the positive predictive value of the test?