SAT Question 7bbfbe70: Nonlinear Functions answer and explanation with Desmos solution

Choice D is correct. It’s given that the mass of a sample of a substance decreases by $24\%$ every $22.96$ minutes. Therefore, after each $22.96$ -minute interval the mass is multiplied by $1-0.24$, or $0.76$. It’s also given that $t$ represents the number of minutes after the lab analyst began observing the sample; therefore, $\frac{t}{22.96}$ represents the number of $22.96$ -minute intervals. The equation that could represent this model is $M=100(0.76{)}^{\frac{t}{22.96}}$, where $M$ is the estimated mass, in grams, of the sample $t$ minutes after the lab analyst began observing it.