Question

Tina and Kylie saw an ad on television comparing different brands of
paper towels. They decided to run their own experiment to see
which towel could absorb the most liquid. They took several brands
of paper towels and cut them into equal sized strips. They put the
strips in small containers. Next they poured water into each
container. After 2 minutes, they pulled the strips out and measured
how much water was left. What was one variable they forgot to
control?

Answer 1

Answer:

They forgot to measure the amount of water poured into each container.

Explanation:

When an experiment is set up, all variables must be established in the same proportion for all experimental units. In this case, for the experiment to be efficient and present true results, it is important that the paper towel strips have the same size, the containers where they will be inserted are the same and they are tested in the same amount of water, that is, each container must contain the same amount of water. However, the amount of water was not measured in the above experiment and this was the variable that the researchers forgot to control, which will harm the veracity of the results.