Question

a cell phone company wants to determine the average amount of data that their smart phone customers use each month. which group would best represent a sample of the population?
one thousand of their customers with the most expensive monthly plans
one thousand of their customers who most recently signed up with the company
one thousand of their customers with a current smart phone data plan
one thousand of their customers who called in for technical support

Explanation:

To determine the average data usage, the sample should be representative of all smartphone customers. Customers with the most expensive plans may use more data (biased). New - signups might have different usage patterns (biased). Customers who called for technical support may not be typical (biased). Customers with a current smartphone data plan are the relevant and likely representative group.

Answer:

one thousand of their customers with a current smartphone data plan