As shown in the following figure: the total number is: 15+ 17+9+8=49 (this book), and the total number of other popular comic books (this book) is 49 15 17 9 8.

(1) According to the data in the statistical chart, each grid represents 2 copies.

(2) According to the statistical chart, storybooks are the most and other books are the least;

(3) 17-8=9 (Ben),

Answer: The most books are 9 more than the least books.