Which of the following are statistical questions? Select all that apply.

1. How many books did the students at this school read over the summer?
2. What is your favorite ice cream flavor?
3. How many letters are in the first name of each person in this class?
4. How many hours do the students in this class sleep each night?
5. How many hours a night do you spend on homework?
6. How many chocolate chip cookies were made in the bakery last week?