This table shows the average height in inches for girls and boys at ages 8, 10, 12, and 14 years. To find the average growth per year for girls from age 8 to age 12, Emma knew she had to find the amount of growth between age 8 and age 12, then divide that number by the number of years between age 8 and age 12.

Emma used this expression: \((60.50 − 50.75)\div4\)

She evaluated the expression using the order of operations.

Write the expression. \((60.50 − 50.75)\div4\)

Perform operations in parentheses. \(9.75\div4\)

Divide. 2.4375

So, the average annual growth for girls ages 8 to 12 is 2.4375 inches. Write a new problem using the information in the table for the average height for boys. Use division in your problem.

The table shows the number of books each of three friends bought and the cost. On average, which friend spent the most per book? Use numbers and words to explain your answer