The sampling technique used at a local restaurant where every 10th customer was asked their opinion of the service at the restaurant as they exited is systematic sampling.What is systematic sampling?Systematic sampling is a probability sampling method where the elements are chosen from a target population by using a fixed sampling interval. The sampling interval is the gap between successive elements in the sample. That is, for instance, if there are 100 elements in the target population and a sample of 20 elements is required, the sampling interval is calculated by dividing the population size by the sample size, in this case, 100/20 = 5, meaning that the sample interval is 5.The first element is picked at random, and the other elements are picked based on the predetermined sampling interval. This means that each kth element in the population is selected for the sample once the first element has been chosen at random. Thus, the first element is selected at random, and the remainder are selected based on the sampling interval.