Problem
To check the accuracy of a machine filling coffee cups, every fifth cup is selected, and the number of ounces of coffee is measured. Which sampling method was used in this situation? Simple random sampling Stratified sampling Cluster sampling Systematic sampling
Solution
Step 1 ：The question is asking about the type of sampling method used in the given scenario. In this case, every fifth cup is selected for measurement. This is a systematic way of selecting samples because a specific 'system' or rule (i.e., every fifth cup) is being followed.
Step 2 ：Therefore, the sampling method used here is systematic sampling.
Step 3 ：Final Answer: \(\boxed{\text{Systematic sampling}}\).
