c) One researcher suggests that plots closer to the old dump site could contain more contaminants than those farther away. How could the sampling procedure be improved to take this into account? O A....

Extracted text: c) One researcher suggests that plots closer to the old dump site could contain more contaminants than those farther away. How could the sampling procedure be improved to take this into account? O A. Use a stratified random sample, stratifying by distance from the dump site. O B. Use a stratified random sample, stratifying by distance from the nearest road. O C. Use a convenience sample, selecting the 18 plots closest to the dump site. O D. Use a multistage sample, stratifying by distance from the dump site and then using a cluster sample within each stratum.


Extracted text: An environmental agency took a map of a region near a former industrial waste dump and placed a grid of 575 squares on it. They collected soil samples from every 18th square and checked each for evidence of toxic chemicals. Complete parts a) through c) below. a) What type of sampling did they use? Choose the correct answer below. O systematic sample simple random sample census es cluster sample b) Is there any sort of bias associated with this sampling procedure? Choose the correct answer below. O A. Nonresponse bias O B. Response bias O C. Undercoverage O O O O