To find the equation of the trend line in slope-intercept form \( y = mx + b \), we first need to calculate the slope \( m \) and the y-intercept \( b \).
From the points given:
- Point (0, 45)
- Point (2, 25)
- Point (3, 15)
- Point (4.5, 0)
We'll use the two points, (2, 25) and (3, 15), to calculate the slope. The formula for slope \( m \) between two points \((x_1, y_1)\) and \((x_2, y_2)\) is:
\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Plugging in the values:
\[ m = \frac{15 - 25}{3 - 2} = \frac{-10}{1} = -10 \]
Now we can use one of the points to find the y-intercept \( b \). Using the point (2, 25):
\[ y = mx + b \implies 25 = -10(2) + b \]
\[ 25 = -20 + b \]
\[ b = 25 + 20 = 45 \]
Now we have both \( m \) and \( b \). The equation of the trend line is:
\[ y = -10x + 45 \]
So the equation in slope-intercept form of the trend line is:
\[ y = -10x + 45 \]