the author had difficulty findind the percentage of people who write with their left hand. if we want to estimate that percentage based on results, how many people must we survey in order to be 99% confident we are with in 2 percentage points of the population percentage? assume that we know nothing about the percentage of the population that writes with their left hand.

A science competition is marked out of 60. James obtains 43 marks, Roy 46 marks and Ben 49 marks. the examination board decided that those who score 80% and above will get a gold award, those who score 70% to 79%  inclusive will get a silver award. what award does each boy get?