The sheer dedication that must've gone into covering the ENTIRE A-Level Maths/Further Maths syllabus is incomprehensible to us mere mortals. You, sir, are a legend.
I wish you were my teacher. I don't know what my teacher was teaching, and why he was teaching these FANCY TERMS; well, now I understand. All credit goes to you sir, my humble wishes for this fruitful channel of yours!
Thanks so much. I was wondering why I was getting a different standard deviation in all my OCR MEI B questions. Now I know they are referring to the sample standard deviation!
I know variance is important in statistics, but I currently only understand it as an intermediate step on the way to calculating the standard deviation. Are there occasions where variance is preferable? Thank you so much for this video :)
That is another calculation: the mean average deviation. It gives a distinctly different and smaller value than the standard deviation. There appears to be a bit of an argument about retiring the standard deviation in favour of it! web.archive.org/web/20140116031136/www.edge.org/response-detail/25401
The standard deviation tells you the average distance each point is away from the mean. So the larger the standard deviation, the more spread out the data is.
Thanks :) Quick question - theres an Edexcel past paper question which refers to Sxy. It looks like it is in reference to correlation between two data sets. Basically it asks to find the PMCC between two datasets and provides Sxx, Syy and Sxy. This is not in my textbook :/
Can you, or someone explain why the square root makes sense. Because when you have the addition of two numbers squared, the square root does not reverse the squares of the numbers being added together. Furthermore, why does sqrooting the whole fraction makes sense?
Essentially it's a comparison of magnitude. It's kind of like when you use Pythagoras' Theorem. Squaring the sides puts squares on each of the sides of your triangle, so that you're comparing areas. a^2 + b^2 = c^2. Then to find c we square root both sides, c = sqrt(a^2 + b^2) which brings them back down to lengths.
In the exam, could you just use your calculator to obtain standard deviation/variance from the data given in the question? What if you don't show your working?
No. To calculate the standard deviation for a set of numbers, you divide by n. Dividing by (n-1) gets you the sample standard deviation, which is used to estimate the population standard deviation. If you are studying OCR MEI, dividing by n is referred to as the root mean square deviation (rmsd).
Dividing by n-1 is the sample standard deviation and variance. If you’re doing OCR MEI then you will refer to dividing by n-1 as the standard deviation and variance, whereas dividing by n is referred to as the root mean square deviation (rmsd) and the mean square deviation (msd)
That's the sample standard deviation s_x which I introduce here: ruclips.net/video/ts9SWUiFn6k/видео.html. OCR MEI on the other hand considers dividing by n to be the root mean square deviation, and dividing by n-1 to be the standard deviation. So different boards expect slightly different things. It is definitely worth checking your exam board's specification for more information.
![A-Level Maths: L3-12 [Data: Comparing Data Sets Problem 2 AGAIN!]](http://i.ytimg.com/vi/7S6NTA9nrYU/mqdefault.jpg)
![A-Level Maths: L3-12 [Data: Comparing Data Sets Problem 2 AGAIN!]](/img/tr.png)
![A-Level Maths: L3-05 [Data: Estimating the Median from Grouped Data]](/img/1.gif)
The sheer dedication that must've gone into covering the ENTIRE A-Level Maths/Further Maths syllabus is incomprehensible to us mere mortals. You, sir, are a legend.
wish they taught like this at school.
this video... amazing. never understood what standard deviation actually was until now. 😁
same! I'm just so glad I stumbled upon his videos...I'm virtually failing my Stats class
you’re literally saving my A level maths
Like that he turned a meaningless formula into something meaningful and easy to understand
It's my last A Level Maths test on Monday and I couldn't have done it without you Jack! Thanks for everything
All the best for Monday! Good luck!
Such a helpful video, need more teachers like this
Thank you sir - you have no idea how much you’ve helped me
I'm watching your videos to learn how to teach my students.
I wish you were my teacher. I don't know what my teacher was teaching, and why he was teaching these FANCY TERMS; well, now I understand. All credit goes to you sir, my humble wishes for this fruitful channel of yours!
Thanks so much. I was wondering why I was getting a different standard deviation in all my OCR MEI B questions. Now I know they are referring to the sample standard deviation!
Thank you so much it makes sense! It's crystal clear!
great teacher! so helpful!!
This man is Goated for real.
I know variance is important in statistics, but I currently only understand it as an intermediate step on the way to calculating the standard deviation. Are there occasions where variance is preferable?
Thank you so much for this video :)
I think there may be in finance, but I'm not 100% sure. I think I would need a university professor to answer it!
@@TLMaths Thanks - with everything else you have going on, I really appreciate that you replied :)
Love your t-shirt sir
Brilliantly explained, cheers Teach :)
You explained this so well thank you so much
great video, I honestly wish my teacher just followed what this video did because I get it now and I didn't when he covered it
You are a legendary teacher
Why do you square root after adding the x-x(bar) s together instead of before? Thanks for the great video also.
That is another calculation: the mean average deviation. It gives a distinctly different and smaller value than the standard deviation. There appears to be a bit of an argument about retiring the standard deviation in favour of it! web.archive.org/web/20140116031136/www.edge.org/response-detail/25401
@@TLMaths Interesting. I'll give it a read. Thanks for the reply
What would a higher standard deviation mean? Can you please explain this to me?
The standard deviation tells you the average distance each point is away from the mean. So the larger the standard deviation, the more spread out the data is.
I appreciate this video
Genius brother , I love your content
Thanks :) Quick question - theres an Edexcel past paper question which refers to Sxy. It looks like it is in reference to correlation between two data sets. Basically it asks to find the PMCC between two datasets and provides Sxx, Syy and Sxy. This is not in my textbook :/
Was this in A-Level Maths or A-Level Further Maths? Can you tell me which exam question it is.
You are you life saver truly thank you very much
Tysm for explaining everything
epic explanation
Thank you sir your the best
Can you, or someone explain why the square root makes sense. Because when you have the addition of two numbers squared, the square root does not reverse the squares of the numbers being added together. Furthermore, why does sqrooting the whole fraction makes sense?
Essentially it's a comparison of magnitude. It's kind of like when you use Pythagoras' Theorem. Squaring the sides puts squares on each of the sides of your triangle, so that you're comparing areas. a^2 + b^2 = c^2. Then to find c we square root both sides, c = sqrt(a^2 + b^2) which brings them back down to lengths.
amazing video!!!!
thank you!
very useful, thanks
In the exam, could you just use your calculator to obtain standard deviation/variance from the data given in the question? What if you don't show your working?
Yes, just use your calculator. You will not have to calculate the standard deviation from a table by hand
Why do we square root n as well as Sxx? I understand square rooting Sxx but not quite sure why we square root n.
The Variance = Sxx / n
The Standard Deviation = sqrt(Variance) = sqrt( Sxx / n)
it is suppose to be square root of 74 divided by (n-1) not n
No. To calculate the standard deviation for a set of numbers, you divide by n. Dividing by (n-1) gets you the sample standard deviation, which is used to estimate the population standard deviation. If you are studying OCR MEI, dividing by n is referred to as the root mean square deviation (rmsd).
@@TLMaths ok I see thank you :)
You sir, deserve a knighthood
this guy is too good at explaining lmfao its a joke
wouldn't it be n -1 not n. that's just what we got taught at school???
Dividing by n-1 is the sample standard deviation and variance. If you’re doing OCR MEI then you will refer to dividing by n-1 as the standard deviation and variance, whereas dividing by n is referred to as the root mean square deviation (rmsd) and the mean square deviation (msd)
Have you got a patreon
I don't
Isn't it n-1 on the bottom?
That's the sample standard deviation s_x which I introduce here: ruclips.net/video/ts9SWUiFn6k/видео.html. OCR MEI on the other hand considers dividing by n to be the root mean square deviation, and dividing by n-1 to be the standard deviation. So different boards expect slightly different things. It is definitely worth checking your exam board's specification for more information.
@@TLMaths ok thanks