We enjoy listening to the news programs and                …

We enjoy listening to the news programs and                                                            Aclassical music on the public radio station, so                                                                Bwe are going to make a contribution during the next, fund-raising campaign.                                                     C                                              

An experiment is performed to determine what factors might i…

An experiment is performed to determine what factors might improve student test scores. Two groups of students from the same class are given the same test at the same time. One group of students received 16 ounces of coffee prior to the test. The other group received 16 ounces of water. The test scores for the two groups are shown below. What is a controlled variable in this experiment?