Answer:
y = (- 5/8)x + 9
Step-by-step explanation:
We are asked to find the equation of the trend line in the scatter plot
The equation of the line can be modeled as
y = mx + c
where:
m = slope of line
c = y-intercept
The slope of the line is defined as the ratio of rise to run, or,
m = rise/run
where
rise = difference in y-values between any two points on the line
run = difference in x -values between the corresponding two points
We are given two points marked in orange to determine the slope
Point 1 is (x1 = 0, y1 = 9) or simply as (0, 9)
Point 2 is (x2 =8, y2 = 4) or simply as (8, 4)
Rise = y2 - y1 = 4 - 9 = - 5
Run = x2 - x1 = 8 - 0 = 8
m = rise/run = - 5/8
The y-intercept c is nothing but the value of y when x = 0; graphically it is the y-value of the point where the line intersects the y-axis
Looking at the graph we see the line intersects the y-axis at (0, 9)
Therefore the y-intercept, c = 9
The equation of the line is
y = (- 5/8)x + 9
