SAT Question 9d95e7ad: Two-variable Data Models And Scatterplots answer and explanation with Desmos solution

Choice C is correct. The predicted increase in total fat, in grams, for every increase of $1$ gram in total protein is represented by the slope of the line of best fit. Any two points on the line can be used to calculate the slope of the line as the change in total fat over the change in total protein. For instance, it can be estimated that the points $(20,33)$ and $(30,48)$ are on the line of best fit, and the slope of the line that passes through them is $\frac{48-33}{30-20}=\frac{15}{10}$, or $1.5$. Of the choices given, $1.5$ is the closest to the slope of the line of best fit.