Question

An urban legend says if you drop food on the floor and pick it up within three seconds, it's safe to eat. Johnny wonder if it's true I want to test the hypothesis [the time of the floor increases the amount of microbes on a toasted bread]. He dropped 400  similar slices of toasted bread from the same

height and onto the same floor condition. 200 slices were left on the floor for 3 seconds. the other 200 slices 10 seconds before picking them up. He measured the amount of microbes on the toaster bread immediately after each drop and analyzed the data with a t-test.

In this study, the type of toaster bread used in the experiment is?

2. the type of toster bread used in the experiment is ?

3. The time of toaster bread left on the floor is ?

4. the amount of microbe on the floor is ?

5. The amount of microbe on the toaster bread is?

independent variable

non of the other choices

control variable

dependent variable

control treatment

Answer 1