Last 2 problems - Not sure how to begin

According to the results of a survey, 37% of 252 people indicated that American football is their favorite sport. Assuming that the percentage remains the same, how many more people should be surveyed to have a margin of error of 2%? Round up to the nearest whole number, if necessary. In order to have a margin of error of 2%, you need to survey D more people. Suppose that the results of a survey show that 47% of people consider summer as their favorite season. How many people should be surveyed in order to have a margin of error of 4%? Round up to the nearest whole number, if necessary. In order to have a margin of error of 4%, D people should be surveyed