Question

The Gallup Poll uses a procedure called random digit dialing, which creates phone numbers based on a list of all area codes in America in conjunction with the associated number of residential households in each area code. Give a possible reason the Gallup Poll chooses to use random digit dialing instead of picking phone numbers from the phone book.

Answer 1

Some people have unlisted numbers.

And today, many people don't have landlines, but depend upon their cell phones. I understand that cell phones can not be dialed randomly.