Question 4 • VA-Probability and Statistics
In cluster sampling, the population is divided into groups, some groups are randomly selected, and everyone in the selected groups is surveyed. Choice D does exactly this by grouping runners according to the seconds portion of their finishing time, randomly choosing two groups, and surveying every runner in them. Choice B also surveys an entire selected group, but the groups are based on running ability and may not represent all participants as effectively.
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