Students in a college made this hypothesis: ‘reaction time will increase as the time you have been awake increases.’ The students set up an investigation to test their hypothesis. This is the method used. 1. Find 5 volunteers willing to stay awake for 24 hours. 2. Keep the volunteers in a room where they can study, use an exercise bike or watch TV as they wish. 3. Provide food, water, coffee and tea as requested. 4. Measure the volunteers’ reaction time every 4 hours using a computer program. (b) What was the independent variable in this investigation?

Time one has been awake

Explanation:

In research, the independent variable is the one that is altered to see the effect that it produces on another variable/s which will be the dependent variable/s.

In this scenario, the amount of time that someone stays awake is the variable being altered to see what effect it will have on the person's reaction time. This therefore makes it the independent variable.

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.

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