2. A media consulting company installs software on the set-top boxes of 100,000 U.S. cable TV customers; every ten seconds, the software records what channel is being viewed. These cable customers have agreed to participate, providing the media company with demographic data, such as age, gender, and income. Each week, the media company publishes rankings of each cable channel. I. What is the population? II. What is the sample? III. Is the study observational or experimental? Justify your answer. IV. What are the variables? V. For each of those variables, what level of measurement (nominal, ordinal, interval, or ratio) was used to obtain data from these variables? Solution 1. All US cable customers 2. 100,000 cable customers participating 3. Observational. No groups or variables are being manipulated. The researchers are simply recording what people are doing. 4. Age, Gender, Income, What channel is being watched, and other demographic variables (unnamed here). 5. Age: ratio Gender: nominal Income: ratio Channel watched: nominal.