Answer:
10 to 25 percent
Explanation:
It is noteworthy that in such research work, in other to validate the study, the supervisors are usually required to call 10 to 25 percent of the respondents to inquire whether the field workers actually conducted interviews.
Remember, if such control policies are not in place, the field workers may not be performimg their duties, that is why the supervisors make such calls to monitor the field workers performance.
