Question

what is the equation of the trend line in the scatter plot?

Explanation:

Step1: Identify two points on trend - line

Let's take two points $(x_1,y_1)=(50,40)$ and $(x_2,y_2)=(80,70)$ from the trend - line.

Step2: Calculate the slope $m$

The slope formula is $m=\frac{y_2 - y_1}{x_2 - x_1}$. Substituting the values, we get $m=\frac{70 - 40}{80 - 50}=\frac{30}{30}=1$.

Step3: Use point - slope form $y - y_1=m(x - x_1)$

Using the point $(50,40)$ and $m = 1$, we have $y-40=1\times(x - 50)$.

Step4: Simplify the equation

$y-40=x - 50$, so $y=x - 10$.

Answer:

$y=x - 10$