Question

nathan and jordan design surveys to determine the average amount of time bicyclists in a race spend training each week. nathan surveys every fifth bicyclist crossing the finish line after a race. jordan surveys the first five bicyclists to finish the race. which best explains which sample is likely to be the most valid?
nathans because his sample was more random
jordans because his sample was more random
nathans because his sample contained elements of the population
jordans because his sample contained elements of the population

Explanation:

A valid sample should be random to accurately represent the population. Nathan surveys every fifth bicyclist crossing the finish - line, which is a form of systematic random sampling. Jordan surveys the first five bicyclists to finish, which is a convenience sample and may not be representative as the first finishers may have different training habits than the general population of bicyclists in the race. Random samples are more likely to be valid as they reduce bias.

Answer:

Nathan's because his sample was more random