The height of bean plants depends on the amount of water they receive.
What is the independent variable?

The higher the temperature of the air in the oven, the faster a cake will bake.
What is the independent variable?

Students measured the temperature of the water at different depths in Lake Skywalker and found that the temperature varied.
What is the independent variable?

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 3 weeks on the diet, the rats’ masses are measured again to see if there has been a decrease
What is the independent variable?

Lemon trees receiving the most water produced the most lemons.
What is the dependent variable (what is measured)?

An investigation found that more bushels of potatoes were produced when the soil was fertilized more.
What is the dependent variable?

The time it takes to run a kilometre in a sweet ParkRun depends on the person’s running speed.
What is the dependent variable?

A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly.
The independent and dependent variables are? (in correct order)

Two groups of students were tested to compare their speed working math problems. Each group was given the same problems. One group used calculators and the other group computed without calculators. 
The independent and dependent variables are? (in correct order)

Students of different ages were given the same puzzle to assemble. The puzzle assembly time was measured.

The independent and dependent variables are? (in correct order)

An experiment is performed on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk. Each plant has the same amount of soil, sunlight, and listens to the same music. In this investigation, the independent variable is ...

An experiment is performed on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk. Each plant has the same amount of soil, sunlight, and listens to the same music. In this investigation, what are the controlled variables?

Mr. S set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. Identify the independent variable.

Mr. B set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. What is the dependent variable?

Mr. B set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. What is the controlled variable?

The librarians want to know which students are checking out what types of books. They are testing "Which type of book do 7th graders check out most often: fiction or nonfiction?" The genre of the book is

An experiment is set up with ten pots to test the effective of fertilizer on plant growth. 5 pots have fertilizer added to the soil, 5 pots do not have fertilizer added to the soil. Each pot has 1 spider plant and 5 cups of soil. The pots are watered once a week with 1/2 cup of water. What is something that would need to be true of the spider plants?

Mr. Bayliss needs your help: He needs to find the constant variables for his experiment. He is trying to determine what shampoo leaves his beard the softest. Which variable would be controlled?