We have taken the tests out of the lecture notes and put them as online practice tests. You can find them linked from the main F2 pages. I do need to change the lectures for that.

How am I supposed to know what you are doing wrong? I work through the answer in the lecture and you can see the workings for yourself (and see that the correct answer is 0.98).

In addition the answers are printed at the back of the Lecture notes.

Thank you for your lecture it was great. Do i need to follow the nest lectures before attempting Variance analysis, or are there some specific chapters I should cover before?

I don’t know if I made a mistake somewhere along in the calculation but i’m having a problem… I used to full figures in thousands for costs and hundreds for units. So, for I have Sum(X) = 2800, Sum(Y) = 420,000, Sum(XY) = 187,000,000, Sum(X^2) = 1,400,000 and Sum(Y^2) = 26,550,000. When I plugged these values into the equation, (the numerator): Square root of [(7*1,400,000)-(2800^2)] X [(7*26,550,000)-(420,000^2)]. My problem is with the values in the last bracket. 420,000^2 is more than (7×26,550,000) which means under the square root I’m getting a negative value. Please Help

SIR I NOTICED THAT YOU MENTIONED THAT YOU SMOKE I WANT YOU TO PLEASE QUIT IT…..BECAUSE IF YOUR NUMBER OF YEARS YOU HAVE LEFT IS BASED ON THE NO. OF CIGARETTES …..CANT AFFORD TO LOSE YOU!!!!YOU ARE MY CHANCE OF SUCCEEDING IN MY EXAMS…..I AM “Y” AND YOU ARE “X” I AM THE DEPENDANT VARIABLE……WITHOUT YOU I SHALL FAIL….lol……..lol………..lol

GOT IT! EXCELLENT! HAVE A HIGHER CHANCE AT PASSING EXAMS! THIS IS DUE TO THE FACT THAT I HAD VERY LIMITED TIME. THE LECTURES ARE REALLY GOOD. UNDERSTOOD IT SO WELL!

loukasierides says

thank you for another great lecture1 i hope F5 will be as easily understood and followed

John Moffat says

Thank you for your comment 🙂

kurbegovicdavor says

Dear Mr Moffat,

Where can I find the tests mentioned at the end of the video?

And thank You very much for great lectures.

Best Regards,

Davor

John Moffat says

We have taken the tests out of the lecture notes and put them as online practice tests. You can find them linked from the main F2 pages.

I do need to change the lectures for that.

kurbegovicdavor says

Dear Mr Moffat,

Thank You for a quick reply.

shreyas says

dear sir,

r is variable cost or fixed cost?

shreyas says

?

John Moffat says

I don’t know why the ‘?’ !!

If it is because I had not replied, it is because we don’t regularly check comments on lectures.

If you want a question answered then you should ask in the Ask the Tutor Forum where we always answer within 48 hours (and usually much,much sooner).

‘r’ is not a cost at all!

It is a measure of how well the variables correlate with each other (or ‘match’ with each other).

I do suggest that you watch all of the lectures on regression and correlation again.

Jegan says

I think I my answer is incorrect actually.

r cannot equal to 0.098 as it has to be a strong positive correlation.

I don’t know where I am going wrong in the calculation.

John Moffat says

How am I supposed to know what you are doing wrong?

I work through the answer in the lecture and you can see the workings for yourself (and see that the correct answer is 0.98).

In addition the answers are printed at the back of the Lecture notes.

Jegan says

Thank you sir.

John Moffat says

You are welcome 🙂

Jegan says

Sir

I got

r = 0.098

I am pretty certain that I am correct. What is the actual value of r, the correlation coefficient, in this example for this video?

loukasierides says

Dear Mr. Moffat,

Thank you for your lecture it was great. Do i need to follow the nest lectures before attempting Variance analysis, or are there some specific chapters I should cover before?

Thanks Again

John Moffat says

No (although it is best to work through the chapters in number order).

loukasierides says

I see, thank you very much

Jonathan says

I don’t know if I made a mistake somewhere along in the calculation but i’m having a problem… I used to full figures in thousands for costs and hundreds for units. So, for I have Sum(X) = 2800, Sum(Y) = 420,000, Sum(XY) = 187,000,000, Sum(X^2) = 1,400,000 and Sum(Y^2) = 26,550,000. When I plugged these values into the equation, (the numerator): Square root of [(7*1,400,000)-(2800^2)] X [(7*26,550,000)-(420,000^2)]. My problem is with the values in the last bracket. 420,000^2 is more than (7×26,550,000) which means under the square root I’m getting a negative value. Please Help

John Moffat says

You have got the sum of Y^2 wrong – it should be 26,550,000,000 🙂

Jonathan says

ahh, thanks!

Sandyp says

For Example 2. the ending for b was 6.7857, but when converted to units is was not 67.86. If the units were in hundreds, why is the answer not 678.57

John Moffat says

The costs are in 1000’s which gives 6785.7 for b, but the units are in 100’s, which makes b 6785.7/100 = 67.857

Sandyp says

Thank u

BELLO OLAIDE TITUS says

Pls sir, could you explain this in another form as I didn’t get how u applied 1000s and 100s

puntusha says

my biggest wish is to be in london and listen to you in live, thank you a lot

Hoa says

thank you for all the lessons! Wishing you – the lecturer and organiser team all the best!

Accountaholic says

Did you get ‘n’ in Question 1 by putting the numbers in formula for ‘b’? Thanks 🙂

John Moffat says

If you mean question 1 in the test at the end of the chapter, then the question says that there are 11 pairs of data – so n = 11 !!

accakeisha says

SIR I NOTICED THAT YOU MENTIONED THAT YOU SMOKE I WANT YOU TO PLEASE QUIT IT…..BECAUSE IF YOUR NUMBER OF YEARS YOU HAVE LEFT IS BASED ON THE NO. OF CIGARETTES …..CANT AFFORD TO LOSE YOU!!!!YOU ARE MY CHANCE OF SUCCEEDING IN MY EXAMS…..I AM “Y” AND YOU ARE “X” I AM THE DEPENDANT VARIABLE……WITHOUT YOU I SHALL FAIL….lol……..lol………..lol

John Moffat says

@accakeisha, I will try 🙂

filorods2002 says

GOT IT! EXCELLENT! HAVE A HIGHER CHANCE AT PASSING EXAMS! THIS IS DUE TO THE FACT THAT I HAD VERY LIMITED TIME. THE LECTURES ARE REALLY GOOD. UNDERSTOOD IT SO WELL!

mannie1111 says

very very helpful lessons. God bless ya!