write an equation in slope - intercept form of the trend line.

Explanation:

Step1: Identify intercept point

The trend line crosses the y-axis at $(0, 45)$, so the y-intercept $b = 45$.

Step2: Find second trend line point

The trend line passes through $(3, 30)$.

Step3: Calculate slope $m$

Use slope formula $m=\frac{y_2-y_1}{x_2-x_1}$ $m=\frac{30-45}{3-0}=\frac{-15}{3}=-5$

Step4: Write slope-intercept equation

Slope-intercept form is $y=mx+b$. Substitute $m=-5$ and $b=45$.

Answer:

$y = -5x + 45$