What is a testable hypothesis to test one employee's prediction that if we serve coffee in Styrofoam cups then it will stay warm longer than if we serve it in ceramic mugs?

A testable hypothesis could be: "If we serve coffee in Styrofoam cups and in ceramic mugs, the temperature of the coffee in Styrofoam cups will decrease at a slower rate compared to the coffee in ceramic mugs over a 60-minute period." This hypothesis can be tested by measuring the temperature of the coffee in both types of containers at regular intervals to compare the rate of temperature decrease.