The probability of a randomly selected adult in one country being infected with a certain virus is 0.004. In tests for thevirus, blood samples from 19 people are combined. What is the probability that the combined sample tests positive for thevirus? Is it unlikely for such a combined sample to testpositive? Note that the combined sample tests positive if at least one person has the virus.

a. The probability that the combined sample will test positive is __.(Round to three decimal places asneeded.)

b. unable to see

c. unable to see