Suppose the probability of contracting a certain disease is p = 0.0004 for a new case in a given year.What's the expected number of new cases in a year in a town where 4,000 people do not currently have the disease?
A)0.16
B)1.6
C)16
D)0.0004
E)0.10

Question

Quizplus · Accepted Answer

The expected number of new cases can be found by multiplying the probability of contracting the disease (p) by the number of people at risk (4000) who do not currently have the disease:

Expected number of new cases = p x number of people at risk
Expected number of new cases = 0.0004 x 4000
Expected number of new cases = 1.6

Therefore, the expected number of new cases in a year in the given town is 1.6. Thus, the best choice is B.

Suppose the Probability of Contracting a Certain Disease Is P