In each of the following situations, the sampling frame does not match the population, resulting in undercoverage. Give examples
of population members that might have been omitted. The population consists of all 250 students in your large statistics class. You plan to obtain a simple random sample of 30 students by using the sampling frame of students present next Monday. Here is how I see it. There might not be all 250 students in class on that Monday. Is that what they mean by under coverage?
Based on your question that ask where each situation and the sampling frame doesn't match the population, resulting in under coverage. The possible answer to your question is , under coverage in a random sampling where the result that you get is still just a partial of the whole but it could be done in anytime as long as the number of people are still there. It means that the sampling result do not just base in one session of sampling.
