Tell which sampling technique was used. 36 points.
1. in a large school district, all the math teachers were polled to see how long their students took to complete homework assignments.
2. every 25th customer was entered into a sweepstakes.
3. managers at a restaurant selected 3 employees names out of a bowl.
4. news reporters of a large city are divided into stations and according to whether they are radio or tv. then 10 are selected at random.