SAT Question f85bbf7a: Inference From Sample Statistics And Margin Of Error answer and explanation with Desmos solution

Choice B is correct. It's given that of the $100$ students who were selected at random from all students in the school, $32\%$ expressed interest in the club. It's also given that based on the sample mean and the margin of error, the faculty expects that between $24\%$ and $40\%$ of all students in the school would express interest in the club. These values are calculated by subtracting the margin of error from $32\%$ to get the lower bound, $24\%$, and by adding the margin of error to $32\%$ to get the upper bound, $40\%$. It follows that the margin of error can be calculated as the difference between $32\%$ and $24\%$ or between $40\%$ and $32\%$. The difference between $32\%$ and $24\%$ is $\left(32-24\right)\%$, or $8\%$.