Answer:
B. 17 books
Explanation:
We have been given a box plot. We are asked to find interquartile range for our given box-plot.
We know that interquartile range is difference of upper quartile and lower quartile.
We know that first line of box plot represents lower quartile and last line of box represents lower quartile.
Therefore, 17 books is the interquartile range of the number of books read by the students in Mr. Ford's class.