Amani is calculating the slope of the trend line in the scatterplot below. 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.
Let y equal number of pushups a day. When x = 1, y = 8. When x = 2, y = 10. 10 is a factor of 30. Multiply y by 3. However, since x increases by 1 when y increases by 2, multiply x by 6 (2*3). That equals 12. Therefore, when x = 12, y = 30.
You can answer this problem using the midpoint formula, but we can work out the 4th vertex by just logically thinking it through by first drawing out the rhombus on an x-y coordinate plane. I wrote the answer out on paper since it is easier than typing. Let me know if you have any questions.
