1) Yes, because you will need to collect data that varies in order to answer this question. Teachers will have various years of experience and you would need the tools of statistics to answer the question.
2) Yes, because you will need to collect data that varies in order to answer this question. Sixth-graders will have a variety of favorite foods and in order to figure out the most popular, you would need the tools of statistics to answer the problem.
3) No, because you will not need to collect data that varies in order to answer this question. All you have to do is measure the height of building and you are done. You don't need the tools of statistics to answer this, you just need a really long ruler LOL!