To find the equation of the trend line in slope-intercept form (y = mx + b), we first need to determine the slope (m) and the y-intercept (b).
From the points provided:
- Point 1: (0, 45)
- Point 2: (2, 25)
- Point 3: (3, 15)
- Point 4: (4.5, 0)
Let's use the first two points to calculate the slope (m).
The slope formula is: \[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Using the points (2, 25) and (0, 45): \[ m = \frac{25 - 45}{2 - 0} = \frac{-20}{2} = -10 \]
Now that we have the slope (m = -10), we can use one of the points to find the y-intercept (b). We can use the point (0, 45) since it directly gives us the y-intercept.
The equation of the line becomes: \[ y = -10x + b \]
Substituting (0, 45) into the equation to solve for b: \[ 45 = -10(0) + b \implies b = 45 \]
Thus, the equation of the trend line in slope-intercept form is: \[ y = -10x + 45 \]
So, the final answer is:
y = -10x + 45