Question

A test for the presence in the blood of antibodies to HIV, the virus that causes AIDS, gives a positive result with probability about 0.004 when a person who is free of HIV antibodies is tested. This is called a false positive. A clinic tests 5000 people who are all free of HIV antibodies. What is the probability that between 10 and 15 people in this sample will receive a false positive reading?

Answer 1

In this x=0,1,2- W -56 ;P: 0.004 using binomial distribution P(x=se) = (%) 2) pe ce-an- The probability that between 10 and 15 people in this Sample woull receive a false positive reading is P(losx515) = P(X=10) +PCX = 11) + ACX=12)+P(x=13) +Plx=14)+ P(X=15) 10000)(0.004)°C-0.004500010 it ooo) (0.004) C1-0.004) +(5.0) (0.004)(1-0.004) + suvo) (2004) (1-0.004) +(5990) (0.00454 C1-0.004) +(So) (0,004) Cl-0.004) Plios x515) 5000-11 Sooo12 13 S00043 5000-4 500-15 0.1511