Question

question 1 - 10
a group of students is trying to determine which detergent will best remove an oil stain. they place five separate dabs with oil blot that each of the stains is different in size. they repeat each test two - times, while:
use a different type of oil for each test.
vary the size of the oil stain on each piece of cloth.
change the amount of detergent used during each trial.
place each oil stain on separate, but identical, pieces of cloth.

Explanation:

To determine which detergent removes an oil stain best, variables other than the detergent should be kept constant. Using a different type of oil, varying the size of the stain, or changing the amount of detergent used would introduce additional variables. Placing each oil - stain on separate but identical pieces of cloth helps control the fabric variable, allowing the focus to be on the effectiveness of the detergent.

Answer:

Place each oil stain on separate, but identical, pieces of cloth.