Two-variable data: Models and scatterplots SAT question

Choice C is correct. It's given that the scatterplot shows the relationship between two variables, $x$ and $y$, and a line of best fit is shown. For the line of best fit shown, for each increase in the value of $x$ by $1$, the corresponding value of $y$ increases by a constant rate. It follows that the relationship between the variables $x$ and $y$ has a positive linear trend. A line in the xy-plane that passes through the points $(a,b)$ and $(c,d)$ has a slope of $\frac{d-b}{c-a}$. The line of best fit shown passes approximately through the points $(0,0.25)$ and $(4,2)$. It follows that the slope of this line is approximately $\frac{2-0.25}{4-0}$, which is equivalent to $0.4375$. Therefore, of the given choices, $0.44$ is closest to the slope of the line of best fit shown.

Choice A is incorrect. This is the slope of a line of best fit for a relationship between $x$ and $y$ that has a negative, rather than a positive, linear trend.

Choice B is incorrect. This is the slope of a line of best fit for a relationship between $x$ and $y$ that has a negative, rather than a positive, linear trend.

Choice D is incorrect and may result from conceptual or calculation errors.