Working people who are older, aged from 20-60 years, career to earn money to feed themselves, and family may work. Then the study. Set the size of the package according to the schedule of krejci and Morgan.& Morgan confident level of 95 from those who work in the Phitsanulok municipality of the end, 48651 people. The samples were 381 people and the increasing sample size is 400 people. To prevent the loss of data.
การแปล กรุณารอสักครู่..
