Chapter 4, Problem 39SGR

To determine

To find: The best fit linear equation in $y=mx+b$ form.

Answer to Problem 39SGR

Line of best fit is $y=210x+230$

Explanation of Solution

Given information: There are two points (2,650) and (5, 1280) passes through the best fit line.

Formula: Let’s find slope using formula $m=\frac{y_2-y_1}{x_2-x_1}$ . Then plug in this value for ‘m’ and one point into the equation to find the value for ‘b’.

Calculation:

Let’s find slope of the line using formula and the two points (2,650) and (5, 1280)

  $m=\frac{1280-650}{5-2}$

= $\frac{630}{3}$

=210

Plug in ‘m’ as 210 into $y=mx+b$ . We get $y=210x+b$

Now, use one of the given points to find the value for ‘b’. Let’s use (2,650).

  $650=210(2)+b$

  $650=420+b$

Subtract both sides 420.

  $b=230$

Plug in the value of ‘b’ into the equation, we get $y=210x+230$