If kendrick decides to watch t. v. instead of go to the gym, the is a missed workout.

opportunity cost

Explanation:

Opportunity cost refers to the conditions where scarcity demands that one choice be chosen over another. It simply means that taking advantage of a situation means missing another opportunity. Although it is an economical term, now its sphere has been increased to different fields such as time, mechanical output, person-hours, etc.

As per the question, Kendrick taking the opportunity to watch T.V and missing another one (Gym) is a perfect example of opportunity cost.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.