=> ()ѱȸ翬 ڷ => http://www.ksrc.or.kr => 062-362-0778, : 011-601-5463 => => 5․18 31ֳ Ͽ ֽùε ǰ ̴. => => 1. : ȭ => 2. : => - ֱ 20 ̻ 80 ̸ 400 => 3. Ⱓ : 2011 5 20 5 22 => 4. ǥ : ȭǥ(stratified random sampling) : ֱ α , ɺ Ҵ ȭ ȭȣο ڸ Ͽ. => 5. ǥ ִѰ : 95%ŷڼؿ 4.89% => 6. : ܹ ѱȸ翬 => => |