sam conducted a survey to find out the favorite weekend activity of the students in his middle school. he asked 20 of his classmates. he found out that the favorite weekend activity of his middle school is playing video games because 75% of the students he surveyed liked to play video games. explain why sam’s sample may not be valid. provide 2 or 3 sentences of explanation with facts to support your answer. how could sam improve his survey to be more representative of his school?