Chapter 1, Problem 25PS

Suppose that 10,000 customers in a retailer s customer database are categorized by three customer types: 3,500 prospective buyer, 4,500 first time buyers, and 2,000 repeat (loyal) buyers. A sample of 1,000 customers is needed.

a what type of sampling should you do? Why?

b. Explain how you would carry out the sampling according to the method started in $\left(\text{a}\right)$ .