Question

State police set up a roadblock to estimate the percentage of cars with up-to-date registration, insurance, and safety inspection stickers. It would be too inconvenient and costly to check every vehicle that passes through a checkpoint, so they decide to stop about 1/20 of the vehicles. Why would a simple random sample be unreasonable for this situation?

A. If the police used a list of registered automobiles, they would have to track down each of those owners and the unregistered owners would not be on the list.
B. The bus. police might choose cars based on how they look.
C. If they randomly picked cars at a grocery store it wouldn't be a good sample size

Answer 1

A simple random sample would be unreasonable for this situation because it may result in a biased sample that does not accurately represent the population of cars with up-to-date documentation. Instead, the state police could use a different sampling method to ensure that the sample is representative.

Step-by-step explanation:

A simple random sample would be unreasonable for this situation because it would not provide an accurate representation of the population of cars with up-to-date registration, insurance, and safety inspection stickers. In a simple random sample, each car would have an equal chance of being selected. However, this may not capture the true proportion of cars with up-to-date documentation because certain types of cars (such as older, run-down cars) may be more likely to be stopped at a roadblock. This would result in a biased sample that does not reflect the population accurately.

Instead, the state police could use a different sampling method, such as stratified sampling or systematic sampling, to ensure that the sample is representative of the population of cars passing through the roadblock.