Our challenge is to find something in our control that will change our DV to a satisfactory level. In other words, we identify an IV upon which we believe our DV depends. A variable can be anything that takes on different values. For example, we each represent thousands of variables including age, sex, height, net worth, marital status, serum cholesterol level, and political party. For example, early in life, your height depends on your age rather than vice versa.
Revenues depend on price, competition, demand, etc.
We are now free to move on to other phases of the Problem Analysis process.