Question

3 - marshmallow muscles
larry was told that a certain muscle cream was the newest best thing on the market and claims to double a person’s muscle power when used as part of a muscle - building workout. interested in this product, he buys the special muscle cream and recruits patrick and spongebob to help him with an experiment. larry develops a special marshmallow weight - lifting program for patrick and spongebob. he meets with them once every day for a period of 2 weeks and keeps track of their results. before each session patrick’s arms and back are lathered in the muscle cream, while spongebob’s arms and back are lathered with the regular lotion.

time	initial amount	after 1 week	after 2 weeks
spongebob	5	9	17

which person is in the control group?
what is the independent variable?
what is the dependent variable?
what should larry’s conclusion be?

Explanation:

1. Which person is in the control group?

In an experiment, the control group is the one that does not receive the experimental treatment (here, the special muscle cream). SpongeBob’s arms and back are lathered with regular lotion, so he is the control group.

The independent variable is the factor manipulated in an experiment. Here, the type of lotion (special muscle cream vs. regular lotion) is what’s changed, so the independent variable is the type of muscle cream (or the application of the special muscle cream).

The dependent variable is what’s measured (depends on the independent variable). Here, the amount of muscle power (or the numerical value representing muscle amount/strength, as seen in the table) is measured, so it’s the amount of muscle (or muscle power/strength).

Answer:

SpongeBob

2. What is the independent variable?