2.  The Control Group  The Independent Variable  The Dependent Variable  What should the conclusion be?  How Could the Experiment Be Improved?

3.  Homer notices that his shower is covered in a strange green slime.  His friend Barney tells him that coconut juice will get rid of the green slime.  Homer decides to check this out by spraying half the shower with coconut juice and the other half with water.  After three days of “treatment” there is no change in the appearance of the green slime on either side of the shower.

4.  Bart believes that mice exposed to microwaves will become extra strong  He placed 10 mice in a microwave for 10 seconds.  He compared these to another 10 mice that had not been exposed by placing a block of heavy wood in front of their food. Mice GroupCould move block Could not move block Exposed to Microwaves 82 Not Exposed73

5. Subject AOld Powder30 minutes of itching Subject BNew Powder45 minutes of itching  Krusty was told that a certain itching powder was the newest best thing on the market, causing 50% longer lasting itches. He buys the new powder and compares it to his old powder by testing the two products on two different subjects

6.  Smithers thinks that a special juice will increase the productivity of his workers.  He creates two groups of 50 workers each and assigns them the same task, stapling sets of papers.  Group A is given the special juice to drink while they work.  Group B is not given the special juice.  After an hour, he counts how many stacks of papers each group has made. GroupNumber of Stapled Papers A1,587 B2,113

7.  Describe how Lisa would perform this experiment  Identify the control group and the independent and dependent variables  Lisa Simpson is working on her science project: “Does Rogooti (a commercial hair product) affect the speed of hair growth?” Her family is willing to volunteer for the experiment.