Question

Following a recent malware attack it was found that approximately 5% of the
student population have laptops which have been infected with a dangerous piece of
spyware. The Department of Computer Science in have developed a new diagnostic test for the identification of the spyware which is positive in the case of 99%
of infected laptops and in 2% of non-infected laptops. Calculate the probability that a
laptop which tests positive is actually infected with the spyware virus.

Answer 1

$P=\frac{0.05*0.99}{0.05*0.99+0.95*0.02}=0.7226$