Last year at a certain high school, there were 144 ninth graders on the honor roll and 80 tenth graders on the honor roll. This year, the number of ninth graders on the honor roll decreased by \( 25 \% \) and the number of tenth graders on the honor roll decreased by \( 20 \% \). By what percentage did the total number of students on the honor roll decrease? Round your answer to the nearest tenth (if necessary). Answer

To find the total number of students on the honor roll last year, we add the number of ninth graders and tenth graders: \[ \text{Total last year} = 144 + 80 = 224 \] Next, we calculate the number of ninth graders on the honor roll for this year. Since their number decreased by \( 25\% \): \[ \text{Decrease for ninth graders} = 144 \times 0.25 = 36 \] \[ \text{Ninth graders this year} = 144 - 36 = 108 \] Now, we calculate the number of tenth graders on the honor roll for this year, with a decrease of \( 20\% \): \[ \text{Decrease for tenth graders} = 80 \times 0.20 = 16 \] \[ \text{Tenth graders this year} = 80 - 16 = 64 \] Now, let's find the total number of students on the honor roll this year: \[ \text{Total this year} = 108 + 64 = 172 \] Now we calculate the decrease in total students: \[ \text{Decrease in total} = 224 - 172 = 52 \] Next, we find the percentage decrease: \[ \text{Percentage decrease} = \left( \frac{52}{224} \right) \times 100 \approx 23.2\% \] Thus, the total number of students on the honor roll decreased by approximately \( 23.2\% \).