1. The given equation is y=8x
where y is the points earned and x is the number of books read by Stephanie.
If she earned 72 points,
She must have read more than 7 books as the points corresponding to 7 books is 56 and she has earned more points than 56.
2.
Number of books read by Stephanie to earn 72 points can be determined as,
Thus, the number of books is 9.
The chart can be filled as,