Question

which is the equation of his trend line?
$y = 2.75x$
$y = 3.05x - 0.6$
$y = 3.25x - 1$
$y = 9.75x - 14$

Explanation:

Step1: Calculate the slope \(m\)

Use the formula \(m=\frac{y_2 - y_1}{x_2 - x_1}\). Take the points \((2,5.5)\) and \((5,15.25)\).
\(m=\frac{15.25 - 5.5}{5 - 2}=\frac{9.75}{3}=3.25\)

Step2: Use the point - slope form \(y - y_1=m(x - x_1)\)

Substitute \(m = 3.25\) and \((x_1,y_1)=(2,5.5)\)
\(y-5.5 = 3.25(x - 2)\)
Expand: \(y-5.5=3.25x-6.5\)
Solve for \(y\): \(y=3.25x-6.5 + 5.5\)
\(y=3.25x - 1\)

Answer:

\(y = 3.25x-1\)