Veterinary epidemiologists are interested in determining the spread of an antibiotic-resistant bacteria among dairy farms across Quebec

Veterinary epidemiologists are interested in determining the spread of an antibiotic-resistant bacteria among dairy farms across Quebec. To ensure that they have an adequate representation of all farm sizes in their study, the epidemiologist classifies each dairy farm in Quebec as either small, medium, or large, and randomly select 25 farms from each size category to be included in the study. Technicians then visit each of the selected farms, and test for the presence of the antibiotic-resistant bacteria. At the end of the study, it was determined that 12% of the farms in the study tested positive for the antibiotic resistant bacteria.

Which of the following statements are true? There may be more than one correct answer, select all that are true.

a. This is an example of simple random sampling.

b. The total number of farms in the study is 25.

c. This is an example of cluster sampling.

d. This is an example of stratified random sampling.

e. The value 12% is a statistic.