Identify each example as Fixed ratio, Variable Ratio, Fixed Interval, or Variable Interval.
1. Checking to see if the laundry is dry (you know it should be dry after around 60
minutes).
2. Getting a free flight for every $3000 spent on a credit card.
3. In an elementary classroom, kids get to put a marble in a jar every time they are
“caught” sharing or being nice to another student. When the jar is full, the class gets
an extra recess.
4. Door salesman or telemarketer.
5. Checking email.