To find the equation of the trend line in slope-intercept form (y = mx + b), we need to determine the slope (m) and y-intercept (b) from the points that the line passes through.
From the description, the line passes through the points (0, 9) and (4, 8). We can use these two points to calculate the slope:
The formula for the slope (m) is: \[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Using the points (0, 9) and (4, 8):
- \((x_1, y_1) = (0, 9)\)
- \((x_2, y_2) = (4, 8)\)
Calculating the slope: \[ m = \frac{8 - 9}{4 - 0} = \frac{-1}{4} = -\frac{1}{4} \]
Now we can find the y-intercept (b). Since the line passes through (0, 9), the y-intercept is 9.
Putting it all together, the equation of the trend line is: \[ y = -\frac{1}{4}x + 9 \]
Therefore, the correct response is: y = -\frac{1}{4}x + 9