Explanation
Correct answer: C.
Choice C is correct. It's given that the scatterplot shows the relationship between two variables, and , and a line of best fit is shown. For the line of best fit shown, for each increase in the value of by , the corresponding value of increases by a constant rate. It follows that the relationship between the variables and has a positive linear trend. A line in the xy-plane that passes through the points and has a slope of . The line of best fit shown passes approximately through the points and . It follows that the slope of this line is approximately , which is equivalent to . Therefore, of the given choices, is closest to the slope of the line of best fit shown.
Desmos solution:
Note: Use two points on the line of best fit and compute rise over run, (2-0.2)/(4-0); Desmos prints the slope as 0.45.
Enter in Desmos:
Reviewed and rewritten by CookSAT
Why the other choices are wrong
Choice A
Choice A is incorrect. This is the slope of a line of best fit for a relationship between and that has a negative, rather than a positive, linear trend.
Choice B
Choice B is incorrect. This is the slope of a line of best fit for a relationship between and that has a negative, rather than a positive, linear trend.
Choice D
Choice D is incorrect and may result from conceptual or calculation errors.