5. People's ideas may change over time in the course of social and economic development. Suppose we conducted two surveys of undergraduates' opinions of "living with parents after graduation" in Year 2000 and 2010 and collected observations as follows: Year No Yes It depends 2000 13 71 16 2010 84 406 158 The researchers are curious about whether young people's ideas have changed in the past decade. (a) Please form proper hypotheses in answering the researchers' question. [20 marks] (b) According to the survey data, did young people change their ideas significantly during the past ten years (at 5% significance level)? Please provide your answer with statistics and the corresponding calculation process. [80 marks]