In 2017 the German Soccer Bundesliga introduced a video to review certain critical plays. However, the system has not been without its controversies. On April 16, 2018 the referee of the game Mainz against Freiburg waved away appeals from the home side for handball in the penalty area, then promptly blew the whistle for halftime. After players of both teams had entered the changing rooms, the referee called the teams back onto the pitch; he had reviewed the penalty appeal for handball and awarded a penalty kick. Mainz scored a goal from the penalty exactly 6 minutes and 44 seconds after the referee had called for halftime. This unfortunate incident led to an outcry among soccer fans in Germany. Nevertheless, a YouGov poll after this event found that 64% of soccer fans in Germany were still in favor of the continued use of the video referee. Suppose the size of this sample was 600 people.

a. Estimate the true proportion of soccer fans in favor of keeping the video referee using a 95% confidence interval.

b. What is the margin of error for this sample?