During the first hour she can hammer 120 nails, the second hour 100 nails, the third hour 90 nails, the fourth hour 60 nails, and the fifth hour 10 nails. Her marginal product in the third hour is nails

Dr. redbull conducts a study to determine whether her new energy drink children perform better on spelling tests. she randomly assigns children to one of two groups: group 1 receives her energy drink and group 2 receives water. she then gives both groups a spelling test and compares the results. which of the following is true about this study? a. group 1 is the dependent variable and group 2 is the independent variable. b. this is a correlational study. c. group 2 is the experimental group. d. the independent variable is the type of drink the children receive.