Does the presence of a small breeze impact how tall daffodils grow? Researchers plant 100 daffodil seeds and separate them, at random, into 2 groups. One group is kept in a room with still air. The other group is kept in a room with a fan blowing. The height of each daffodil is recorded for the next 3 months.

How do business customers feel about the level of support they receive? The business randomly selects 200 customers and asks them to share their opinions.

Do truck drivers get into more accidents than people who drive SUVs? Researchers use police records of automobile accidents over the past year and vehicle registrations to compare the percentage of drivers of vehicles of each type that get into accidents.