Research wireless cell phone using systematic sampling for its simplicity: Any individuals of any age who is a customer with a data plan under various cellular phone carriers will be randomly selected from the lists acquired from these cell phone carriers. The population to be analyzed is 2,000 cell phone users, and a sample of 500 is selected. Starting with the 2nd person on the list, every 4th person will be given the survey.

Question:

What will be measurable data in this case and (assume a survey will be conducted and or data can be obtain). What will be at least two independent variables and one dependent variable. (and assuming they are consistent with the collected data)