NEED THESE TO BE DONE AND SENT BCK IN 20 HRS

In a survey, a sample of 1250 adults were asked, and it was found that 65.6% (820 adults) of them have a Facebook Page. How do we use sample results to estimate values of population parameters?  How accurate is the sample result of 65.6% likely to be? Does the sample size and method of selecting the sample have much of an effect on the results?