It comes from the equation for the mean, which has us divide by the number of terms. If we're looking for how far away values are from the mean, we also need to consider the number of terms. It becomes really interesting with 'n' vs 'n-1' if we're looking at populations vs samples. (n-1 for when we have a sample and want to calculate the population standard deviation). That last part isn't needed for Math AA SL though.
![Cumulative frequency [IB Maths AA SL/HL]](http://i.ytimg.com/vi/7ocIVrJBBwY/mqdefault.jpg)
![Cumulative frequency [IB Maths AA SL/HL]](/img/tr.png)
![Inverse normal - more advanced [IB Maths AA SL/HL]](http://i.ytimg.com/vi/KhBTkU1-v4U/mqdefault.jpg)
![Standard deviation and variance [IB Maths AI SL/HL]](http://i.ytimg.com/vi/QbNf1-R_XVc/mqdefault.jpg)
You are the reason why me and my twin brother are good in math. Thank youuuuuuu soooooo much. YOU ARE A LIFE SAVIOOUR
Yaaay! I'm so glad to know that. Glad I could help. :) Cheers, Mitch
This is life saving
That's wonderful! Cheers, Mitch
thank you so much for these videos! you are just amazing
You are so very welcome!
Thank you very much, god bless
You are so very welcome! Cheers, Mitch
you're amazing, thank you
You are most welcome - happy to help! Cheers, Mitch
for standard deviation i don't really understand why we have to divide it by the number of terms
It comes from the equation for the mean, which has us divide by the number of terms. If we're looking for how far away values are from the mean, we also need to consider the number of terms. It becomes really interesting with 'n' vs 'n-1' if we're looking at populations vs samples. (n-1 for when we have a sample and want to calculate the population standard deviation). That last part isn't needed for Math AA SL though.
@@OSC1990 i see
@@OSC1990 thank you!
Is anything past 8:10 needed for SL?
Yes, you need all of it for SL, including what happens when you multiply by a scalar (what happens to Mean, Standard Deviation and Variance).