Answer:
C. 17.0%
Step-by-step explanation:
A random sampling of human populations is done to check the frequency of a particular infection. The proportion of the individuals in the total population that suffered the infection at any time during the year are counted. The proportion of the individuals infected any time during the year is divided by the total number of the individuals surveyed and the percentage is taken to calculate the prevalence of the infection in the sampled population.
Here, the total number of the individuals that were infected with flu in the last year= 4250.
The total number of the checked individuals= 25,000.
So, the proportion of the individuals infected with flu in this population= 4250/25000 x 100= 17%