The Student Council at Woodlands Middle School is planning a field trip. They polled randomly selected teachers and students and asked
whether they prefer to go to the aquarium or an amusement park.
The results are shown in the table below.

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected