An employee wonders if the average number of days a dog spends in the humane society until adoption is different based on the dog's size (small, medium, large). She selects a random sample of 23 small dogs, a random sample of 34 medium dogs, and a random sample of 45 large dogs from the humane society records and records the number of days each dog spent in the humane society until being adopted. What kind of test scenario is this?