Question

Select the correct answer.
The test to detect the presence of strep throat is 98% accurate for a person who has the disease and 97% accurate for a person who does not have the disease. If 3.5% of the people in a given population actually have strep throat, what is the probability that a randomly chosen person tests positive?

A.
0.0343

B.
0.035

C.
0.06325

D.

Answer 1

C. 0.06325

Work: P(test+) = 0.98(0.035) + 0.03(0.965) = 0.0343 + 0.02895 = 0.06325.