Answer:
The cost is $3.00 for every 2 books.
Explanation:
To calculate the rate (cost per book), we can divide the cost (y) by the corresponding number of books (x):



Therefore, the rate is consistent at $1.50 per book.
Now, to find the cost for every 2 books, we can simply double the rate:

So, the cost is $3.00 for every 2 books.
Note: The points on the graph form a consistent linear pattern, demonstrating that for every 2 books added to the quantity, the cost increases by $3.00.