In surveyselect the SIZE statement looks at the value of a numeric variable and computes a sampling unit size based on the sum of that variable. There are some other issues around which types of samples this may work for though. I would actually filter the data so that only orders with one or more hamburgers were considered and select 100 of those. The question for the boss would be number of hamburgers or number of orders with hamburgers. Imagine the issue of a bus coming through with a football team. One order could potentially have 100 burgers... ... View more