Question

Jordan is calculating the slope of the trend line in the scatterplot below.

On a coordinate plane, a trend line has a positive slope.
How can Jordan use the plot to check the reasonableness of his answer?
His slope should be positive because the coordinates of all the plotted points are positive.
His slope should be positive because the trend line is slanted up to the right.
His slope should be negative because there are plotted points not on the line.
His slope should be negative because the x-coordinate of each plotted point is less than the y-coordinate.

Answer 1

Correct answer: "His slope should be positive because the trend line is slanted up to the right."

Explanation briefly:
- A line that rises as you move right has a positive slope, so visually seeing the trend line slant up to the right is the right check.
- The other statements are incorrect: all points having positive coordinates does not determine slope sign; points off the line don't force a negative slope; and x < y for each point doesn't imply the trend line slopes downward.