The numerical data is a data type expressed in numbers rather than natural language description.
Categorical data is a type of data that can be stored into categories with the aid of names or labels. For example gender, race, etc.
The first question is: On average, how many books does each person in the
United States read each year?
As we need a number of books, it is numerical data, e. g. 10, 5, etc. Also is a statistical question because you need to collect information from a sample to calculate the average.
Then 1. is a statistical question requiring numerical data to answer it.
Question 2. How many acts are in the play Romeo and Juliet?
It requires numerical data but it's a non-statistical question because you don't need to collect data that vary. The acts will be the same in the play, it doesn't change.
Question 3. Which book was read the most by students in the class this summer?
This is a statistical question because you need to collect data that will vary depending on the student, but it requires categorical data, since you will need the name of the books, it's not numerical data.
Question 4. How many books are in the classroom right now?
This is numerical data since you will obtain a number of books, but this information doesn't vary, because you will count the books right now. Then, it's a non-statistical question.
