Out of 10 hospitals in a municipality, a researcher selects one and collects records for a 24-hour period on the types of emergencies that were treated there.

A researcher divides a group of students according to gender, major field, and low, average, and high-grade point average. Then she randomly selects six students from each group to answer questions in a survey.

The subscribers to a magazine are numbered. Then a sample of these people is selected using random numbers.

Every 10th bottle of Energized Soda is selected, and the amount of liquid in the bottle is measured. The purpose is to see if the machines that fill the bottles are working properly.