Can you check the following?

Experiment A: Four groups of rats are first massed and then fed identical diets except for the amount of vitamin A they receive. Each group gets a different amount. After three weeks on the diet, the rats’ masses are measured again to see if there has been a decrease.
57. What is the manipulated (independent) variable?
Ans: vitamin A

58. What is the responding (dependent) variable?
Ans: mass

59. What is the controlled variable?
Ans: diet

1 answer

Right on all counts.