Independent and Dependent Variables

You want to know if heating a cup of water will allow it to dissolve more sugar

What is the independent variable?

• Water temperature

• amount of dissolved sugar

You want to see if playing music makes plants grow taller.

What is the dependent variable?

• Music being played

• Height of plant

You want to figure out which brand of microwave popcorn pops the most kernels so you can get the most value for your money. You test different brands of popcorn to see which bag pops the most popcorn kernels.

What is the independent variable?

• Number of kernels popped

• Brand of popcorn bag

You want to see which type of fertilizer helps plants grow fastest, so you add a different brand of fertilizer to each plant and see how tall they grow.

What is the dependent variable?

• Type of fertilizer given to the plant

• Plant height

You’re interested in how rising sea temperatures impact algae life, so you design an experiment that measures the number of algae in a sample of water taken from a specific ocean site under varying temperatures.

What is the independent variable?

• Ocean temperature

• The number of algae in the sample

You want to know how fast a candle burns.

What is the dependent variable?

• height of candle, measured in centimeters

• Time measured, in minutes

You want to know how many days people can eat soup until they get sick.

What is the independent variable?

• The number of days consuming soup

• The onset of illness

You want to know the impact of a drug on cancer.

What is the dependent variable?

• The administration of the drug

• The impact the drug has on cancer

You want to compare brands of paper towels, to see which holds the most liquid. What is the dependent variable?

• The amount of liquid absorbed by a paper towel

• The brand of paper towel

You want to know whether caffeine affects your appetite.

What is the dependent variable?

• How hungry you are

• The presence/absence of amount of caffeine