Sem 4 Introductory Econometrics PYQ | 2025 PYQ Question 7 | BA (H) Economics | Delhi University | P4

Added: 2026-05-17

[00:00:00]Come on son, now let us learn how to go ahead and find summation xi² in its raw form.

[00:00:05]So, the formula that we are using is this.

[00:00:08]Now ma'am, how is this formula coming? How is this formula coming? So it is very simple.

[00:00:13]We know that when we write in deviation form, the summation xi, if I write it in a very simple form, then our xi in deviation form is capital xi - x times. And now if I want to square these on both sides then I can square them here. And here I can make a submission.

[00:00:39]Here I can put a submission with it.

[00:00:42]So as soon as I do this and rewrite it, after opening it, this formula will appear to us. So now our formula becomes summation xi² = xi² - nx². The interesting thing about this is that we are already given in deviation form the value of summation xi² as 116. The value of n is given to us seven times and x times n is given to us so the whole square of x times will be 81. So when we plug in these values ​​we get the value of capital xi² which is going to be 683.

[00:01:24]Now we have to plug in the simple formula.

[00:01:26]So we know the value of capital xi².

[00:01:29]We had taken out σ².

[00:01:32]The value of n is seven. And small xi² is given to us.

[00:01:34]So when we go ahead and when we put these values ​​in this. When we plug this into this fula, we go ahead and get the answer. And the standard error or standard deviation of beta1 comes out to be 0.2282, okay.