Vaping Study To study vaping (electronic cigarettes) habits of all U.S. vapers, the three largest vaping companies have agreed to provide you with the mailing addresses of their customers at a cost of $8 per customer. You can either pay for all customer addresses, or you can pay for a random sample of customer addresses. Each company sells in a different geographic region of the U.S., so the characteristics of their customers are very different. You can choose to buy customer addresses from just one or all three of the companies. a) Name an appropriate sampling method. [1] b) Describe how to carry out this sampling method. [2.5] c) Justify your choice in a). [1]