This question is asking you for a experiment and in that experiment what is your variable's so I will answer the whole thing for you.
Experiment: My experiment is on if butter popcorn and pop faster then plain, and extra butter popcorn. My hypothesis is that the butter popcorn would pop faster then the other two brands off popcorn. (plain, and extra butter) I pop three bags each of the brands for 1 minute and 45 seconds and then counted how many kernels were left after they been microwaved then added all the kernels together and the brand how has the least pop the most. According to my data the plain popcorn pop the least! To summarized the plain popcorn popped more then the butter, and extra butter popcorn therefore proving my hypothesis wrong.
Variables: There are two variables in every experiment a dependent and a independent variable. Dependent is what your measuring in your experiment and independent is what your testing. My dependent variable would be the kernels since how we are counting how many kernels were not popped in each bag. My independent variable would be popcorn itself.
Hope this helps!
