Answer:
1.
I: Type of tire tread
D: Breaking Distance
C: Model of car, material of road
2.
I: Person’s running speed
D: Time to run one mile
C: Distance of run (one mile)
3.
I: Amount of water
D: Height of bean plants
C: Soil type, amount of sunshine
4.
I: Temperature of oven
D: Time it takes for cake to bake
C: Batter, baking tin
5.
I: Amount of water
D: Amount of lemons
C: Soil type, environment, nutrients
6.
I: Amount of fertilizer
D: Amount of potatoes
C: Soil type, environment, amount of water
7:
I: Depth of lake
D: Temperature
C: Time of day, day of year
8.
I: Amount of lead in gasoline
D: Amount of pollution emitted
C: Amount driven by each car
9.
I: Amount of Vitamin A
D: Difference in weight
C: Other nutrients in diet, time elapsed between measurements
Explanation:
The independent variable is the thing in the experiment that the researcher changed. The dependent variable is the thing in the experiment that changes as a result of differences between the independent variable.
The controls are things that do no change between all variations of the experiment.