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

Question

On a graph, a trend line goes through points (3, 60) and (8, 41).
How can Amani use the trend line to check the reasonableness of her answer?
She should expect the slope to be negative because the line tilts down moving from left to right on the graph.
She should expect the slope to be negative because more points are below the line than above the line.
She should expect the slope to be positive because the line has a positive y-intercept.
She should expect the slope to be positive because all the plotted points have positive coordinates.

Answer 1

To determine the reasonableness of the slope calculation for the trend line between the points (3, 60) and (8, 41), Amani should consider the overall direction of the trend line depicted in the scatterplot.

The best reasoning is:

She should expect the slope to be negative because the line tilts down moving from left to right on the graph.

This is based on the fact that as the x-values increase (from 3 to 8), the y-values decrease (from 60 to 41). A negative slope reflects a decrease in the y-values as the x-values increase, which is indeed what is happening in this case.