Question

After solving normal equations for line of best fit

• A. $m=\frac{n\sum xy-\sum x\sum y}{n\sum x^2+(\sum x{)}^2}$
• B. $m=\frac{n\sum xy+\sum x\sum y}{n\sum x^2-(\sum x{)}^2}$
• C. $m=\frac{n\sum xy+\sum x\sum y}{n\sum x^2+(\sum x{)}^2}$
• D. $m=\frac{n\sum xy-\sum x\sum y}{n\sum x^2-(\sum x{)}^2}$

Answer 1

The correct option is D $m=\frac{n\sum xy-\sum x\sum y}{n\sum x^2-(\sum x{)}^2}$

$y–$ Regression or Dependent Variable or Explained Variable

$x–$ Independent Variable or Predictor or Explanator

The two constants $c$ and $m$ are regression parameters.

We know,

$\sum y=nc+m\sum x$ and

$\sum xy=c\sum x+m\sum x^2$

Direct formula to finding $m$ is

$m=\frac{\sum xy-\frac{\sum x\sum y}{n}}{\sum x^2-\frac{(\sum x{)}^2}{n}}$

$\therefore$ $m=\frac{n\sum xy-\sum x\sum y}{n\sum x^2-(\sum x{)}^2}$

Hence, this is the answer.