Where's the marketing company's criteria for sample selection? How are the communicating and choosing the people? Are they all within the same locality? And no

Where's the marketing company's criteria for sample selection? How are the communicating and choosing the people? Are they all within the same locality? And no 863 is not representative of LA. LA is made up of individual communities and some never leave those communities. Some communities are pass through for commuters. Really important where those 863 are from. All are 863 from a small area? Are some from Pasadena and other from Santa Monica. What about Covina or Redondo? LA or Beverly Hills.