A quality control manager at an automated packaging plant wants to inspect cereal boxes from a continuous conveyor belt. She decides to select the 12th12\text{th}12th box that passes her station, and then every 50th50\text{th}50th box thereafter until the production run of N N\,N boxes is complete. This procedure yields a sample of exactly 80 boxes.
Identify the sampling technique used, and find the range of possible values for the total number of boxes produced, NNN.
Systematic sampling, with 3962≤N≤40113962 \le N \le 40113962≤N≤4011
Systematic sampling, with 4012≤N≤40614012 \le N \le 40614012≤N≤4061
Simple random sampling, with 3962≤N≤40113962 \le N \le 40113962≤N≤4011
Stratified sampling, with 3962≤N≤40123962 \le N \le 40123962≤N≤4012
644 exam-style questions on OCR A Level Psychology Research methods and techniques. Each one has a worked solution and a mark scheme showing where the marks go.