Which of the following are normal equations to fit a straight line trend $y = a + bx$ by the method of least squares?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → $∑y=na+b∑x,∑xy=a∑x+b∑x^2$
For fitting a straight line $y = a + bx$ using the method of least squares, the normal equations are:
$\sum y = na + b \sum x$
$\sum xy = a \sum x + b \sum x^2$
Answer: ∑y = na + b∑x, ∑xy = a∑x + b∑x²