Compare the weights of the backpacks for the students in these three classes.

A dot plot, seventh grade, “backpack weight in pounds”.  The numbers 8 through 25 are indicated. The data is as follows: 8 pounds, 3 dots. 9 pounds, 5 dots. 10 pounds, 7 dots. 11 pounds, 6 dots. 12 pounds, 2 dots. 13 pounds, 1 dot. 14 pounds, 1 dot.

A dot plot, ninth grade, “backpack weight in pounds”.  The numbers 8 through 25 are indicated. The data is as follows: 12 pounds, 3 dots. 14 pounds, 1 dot. 15 pounds, 2 dots. 16 pounds, 2 dots. 17 pounds, 2 dots. 18 pounds, 6 dots. 19 pounds, 2 dots. 21 pounds, 3 dots. 22 pounds, 3 dots. 23 pounds, 1 dot.

A dot plot, eleventh grade, “backpack weight in pounds”.  The numbers 8 through 25 are indicated. The data is as follows: 9 pounds, 1 dot. 11 pounds, 1 dot. 13 pounds, 1 dot. 14 pounds, 1 dot. 15 pounds, 3 dots. 16 pounds, 3 dots. 17 pounds, 2 dots. 19 pounds, 3 dots. 20 pounds, 2 dots. 21 pounds, 3 dots. 22 pounds, 2 dots. 24 pounds, 2 dots. 25 pounds, 1 dot.

A bookstore has marked down the price for all the books in a certain series by 15%.

1. How much is the discount on a book that normally costs \$18.00?
2. After the discount, how much would the book cost?

Match each expression in the first list with an equivalent expression from the second list.

Angles \(C\) and \(D\) are complementary. The ratio of the measure of angle \(C\) to the measure of angle \(D\) is \(2:3\). Find the measure of each angle. Explain or show your reasoning.