Standard Deviation
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- Опубліковано 30 вер 2024
- In this video Paul Andersen explains the importance of standard deviation. He starts with a discussion of normal distribution and how the standard deviation measures the average distance from the mean, or the "spread" of data. He then shows you how to calculate standard deviation by hand using the formula. He finally shows you how to calculate the standard deviation using a spreadsheet.
The calculated standard deviation is 2.7.
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"It's not scary at all, it just means you have to do a lot of work."
That's the scary part
Nailed it
Practise it 20 times and it will become easy.
bighands69 JEWLY ANDERS CONFIRMED! ( I DON'T CARE IF I SPELLED IT WRONG!)
by
Lol
sometimes at night i cry myself to sleep
+calculator cake i try to drink paint to easy the pain i have with maths
often times i will try to also drink away the pain....with bleach
Sometimes it's not enough and u just have to take bleach into the exam in a water bottle but make sure it's clear bleach so they think it's water 👌
Same
#the AP bio experience.
pov: you're a sophomore who blindly chose AP Biology as your class and you are now deeply regretting your decision
POV you’re a junior in the same boat 😢 how’s your junior year going
POV freshman 🤚
@@dolly2644honors bio😢
I like how most statistics video always say "don't be scared".
It's kinda soothing, in a way.
Yeah just like how yelling "RELAX" in someone's face gets them to relax
Like the doctors, when they say "It won't hurt a bit"
its because in math's statistics is easy. but for us its hard..
It's like a biblical angel trying to approach you without spooking you
Who here from AP bio
Me
Me
Yea
Seriously? Why couldn't my chem teacher just explain it to me like this. THANK YOU!
Exactly! The teachers are dumb! ))))
oh well this is for my bio
Dude you could seriously teach ALLLLL OF MY MATH CLASSES!!! It took you 7 minutes to teach something that took 9 weeks to learn.
Thank you Mr.Anderson for presenting this nice informations
Chalak Mariwany You are very welcome. I'm especially happy to hear that this video is helpful because standard deviation is a very important topic.
+Bozeman Science can you do a stand deviation video to explain this formula for standard deviation that we are learning in school o=(x1-u)2 +(x2-u)2+...+(xn-u)2/N?
it was very benificial to me..thank you.
Mr. Andersen, you saved my life in 15 minutes with this tutorial! If I were going to have more children I would not hesitate to name them after you. I looked at this twice, and was able to solve the second problem and get it right! I looked countless other videos and all I got was crickets. The way you explained it will be easier to understand when testing time comes around. I have always had a fear of math, but I have never felt more confident since finding your lectures. I am 46, and I have 5 classes left before I graduate with a degree in Health Information Technology next spring. Whoever said you can't teach an old dog new tricks was severely incorrect. Once again, I thank you and bow in your direction!
damn bruh
Officer, the simp is right here
@@SkylabBeats they were just being polite why is this considered simping
you saved my college career
no because hes hot and good at math lmao
"Don't be scared of the Summation Sign, it just means you have a lot of work."
But I'm scared of work....
Why’d I get 0.67
Hey! I've been watching your videos for all of my chemistry and math courses for the past 4 years and I just want to thank you from the bottom of my heart for making these videos! Knowledge is power and you are giving that to everyone who seeks out help through youtube. You are wonderful. Thank you so much!
Thanks but why did you use "n-1" instead of "N"? 🌹
When sample size is less than 30, the formula with n-1 is used.. If the sample size is more than 30,only n is used.
@@sayantiacharyya2108 why though?
@@forgedwithsteel My professor said if there's 30 chairs but you're sitting in a chair, then at that moment there's only 29 other chairs you can go sit at. So degrees of freedom is (n-1), hence how many chairs are free. If more than 30 chairs, n-1 would skew the data and make it inaccurate, hence for bigger populations, n-1 isn't used. Hope this helps :D.
I am taking a statistics class right now online and find that it is a little difficult for me to get a handle on, so this video helped me out so much by watching someone actually did the an example of what I need to do. I am a visual learning so this helped so much. Thanks
This makes so much more sense now thank you so much! Im taking AP bio as a junior so this was very confusing at first but you explained it perfectly! thank youuu!
Well this is one of the best videos out there but for people who want direct direct steps here ya go:
Step 1: Find the mean in your data. (Add all up, Divide by how many values)
Step 2: Subtract the mean from each value of your data, and square the answer. Do this for all values
Step 3: Add up all results from new values, and divide by how many values (Should be same No. of values from step 1)
Step 4: Square root the answer you got from step 3. The answer you get is the standard deviation
You da man Mr. Anderson
How ya been after 6 years
@@stephenthomas6173 not having to worry about this for the past 6 years has definitely been nice. Graduated college and have a job now lol, time flies 😅
@@DynamicDurge Damnnnn I’m just starting to learn bout this
@@DynamicDurge congrats on graduating though even though I’m late
@@stephenthomas6173 appreciate it! Definitely light at the end of the tunnel
Thanks for the video!! Learning from you in 2019 even though you uploaded this in 2012
my numerator is 30, denominator is 3.6-1, did the division and square ''rooted'' the ans and im getting 3.4, 3. fucking 4, why is that can i get some help here it will be much appreciated, thank you.
Teacher, you have done a great job, don't forget to use parenthesis before squaring the numbers. For example, if you have negative 2 with an exponent 2 without a parenthesis, the answer is negative four (-4). On the other hand, if you use a parenthesis (-2) with an exponent 2, the answer is positive 4.
Robert is right. Those are two different notations that produce different results. " -2 ² " is equivalent to " (-1) * (2)² " which is not the same thing as " (-2) ² ".
Im pretty sure everyone who is studying standard deviation would know this
Thank you so much for your videos.
I love how clear, relaxed and simple you explain. I used to always watch your vids when I was in high school and now I m doing my first year of Uni, still watching your vids, Thank you X
this was a phenomenal representation on standard deviation! thank you!
I thought the formula for standard deviation is √∑(x-µ)^2/N
and the formula in the video: √(x-x̄)^2/n-1 is standard sample?
someone please help.
That's because the one you're using is for an actual population and the one he is using is for sample ( which uses an estimated sample size of the population). Because of that, two of the symbols change but they mean the same thing and for a sample size, you use n-1 because it's not the actual population.
It was a fricking lit day. I was driving a LIT BLUE SPORTS CAR up an oddly cubic mountain. When I reached the darn top, I drove to the hospital for no hecking reason in particular. When I arrived, I diligently drove my LIT BLUE SPORTS CAR INTO THE HOSPITAL. When inside, I proceeded to drive the car all over the hospital, making sure to hit all of the staff inside and make them scream, “OOF”.
Suddenly, my greatest enemy appeared. She said the worst thing imaginable. “Sir, get out.” is what she said, except with much worse grammar. So, being the smart person I am, I said yeet and dabbed my way past her and into the emergency room. Then, minutes later, the police arrived (Because the living staff called the police on their OnePlus 6T) and they were searching for me. Then I drove out of my hiding spot and THEY SAW ME AND MY LIT BLUE SPORTS CAR.
I had to make use of my surroundings to hurry to make my great escape. So, I obviously just tried to take the hospital’s elevator. (While in the LIT BLUE SPORTS CAR) Unfortunately, the elevator was NOT WORKING, and the FRICKING police whipped up to me as they witnessed me attempting to enter the elevator in the LIT BLUE SPORTS CAR. They were shooting me with their useless pea shooters that they call guns. So I just backed up and hit them while playing Despacito on the radio. Then I defenestrated my LIT BLUE SPORTS CAR straight out the window, which had depression.
A few seconds later, I noticed something terrible in the back seat. A POLICE OFFICER spinning a fidget spinner. So, I smartly just proceeded to drive my LIT BLUE SPORTS CAR straight off a cliff and jump out in time to not be brought down with it. In the explosion that lied at the bottom of the cliff, I saw the police walking out of the rubble, unharmed. Shocked, I jumped in the battle bus that I spawned in front of me and drove back to the hospital to cause more destruction.
Unfortunately for me, the police were still there waiting for me. And they were blocking the entrance! Obviously, I drove my BATTLE BUS into the HOSPITAL, but it DIDN’T FIT. I had to think fast, and luckily they have plants in the front of the hospital, so I hid behind them. Sadly, they found me in my makeshift hiding spot and I have to use my UMBRELLA as a shield to evade their harmless bullets. Then I swiftly hid in the MRI machine and ALT+F4-ed. I was never caught.
I keep getting 4.2 instead of 2.7 for the practice one at the end /:
Well everything is nice and good, until you get 35 of values.
Ex. Vortex flowmeter yielded 35 values of frequency corresponding to a constant flow rate: 108.0;109.0;108.1;109.3... for all 35 values.
Is there no other way to find the standard deviation, other than plotting everything in Excel and finding those values...
For a person with a Linguistics background, your explanation was awesome. Very simple and clear and you also combined both formulae with an Excel work. I love that and thanks a million again!
Now, I understand what it means Standard Deviation is the Square Root of the Variance :)
no matter what I do, I still come up with the answer 3.4. what am I doing wrong?
I got 3.4 too!
best explanation ever!!! i totally understood it i was getting so scared of how to do this standard deviation thanks for the explanation
so uh....anyone else got the final this week?
Waken I'm watching this right now cuz I have a midterm in an hour 😂
Can you please make more math videos
So much easier learning from here than my grad school class. Why the heck do they make it so confusing for the tuition I freakin pay!
Finally someone who knows how to explain this: rationale and calculation. Great!
What happens if you have a large number of data sets, like 40. How would you calculate the standard devation?
If i'm not mistaken those are considered outliers, and wouldn't be included in the standard deviation.
i think Elena means is like 40 diffrent data values, not one data value that is equal to 40.
This was really helpful! Got standard deviation so quickly with this, keep up the good work!
THANKYOU FOR THIS VERY AWESOME SORRY FOR CAPITALS CANT TURN OFF BUT AWESOME VIDEO
I'm late to say this, but anyways Bozeman Science has been my favorite video tutor to remember old topics and learn new concepts since high school and now college.
Wow, thank you. The first 6 minutes of this taught me more than an entire lecture and recitation on the subject I had previously. Way to go, academia standards, eh?
Thank. You. Great. Video.
How come the formula is different from my math book and other videos?
Mine is simply n, not n-1
n is for population. n-1 is for sample size
Oh, I understand it now. Thank you!
He explained this so well, I understand it. However, I keep getting my practice problems wrong! I wish I was a math wizard :(
Honestly I feel like he's taught me more than my own teacher....
That was extremely helpful thank you for doing what you do.
Sir, thank you for the video. You helped me a lot.
Totally confusing. Probably ok for students comfortable with math. If not, his explanations are opaque.
Hello everyone.
Could you help me please?
• There are 20 numbers.
• Standard deviation: 5 or 4,5
• Average(Mean): 3
• Numbers between 1 and 10
Which are these numbers?
Thank you for your interest.
Cordinally
I dont know how I got my answer wrong, I have followed step by step. To make sure my calculator isnt acting up I did the first example as well and that worked fine! IM SO CONFUSED
Thank you! You really help me out.
what is exactly this 1.58 value means?
I love statistics, testing data...so interesting, yet I still don't have everything conceptually. Like, when you add up all of the standard deviation entries and get 10, well what does that mean? Ten? I understand what SD is but the other cognitive pedagogical concepts sometimes don't form in my head.
Can someone help with this question,
The weights of a coffee shop’s muffins are normally distributed
with mean 100g and standard deviation 5 g. Show how to determine the
proportion of muffins that are at least 96 g.
My textbook has a different formula which is sqrt[1/n * summ[(x-mean)^2]] not 1/(n-1). Why is that?
I wanted to understand the concept why in formula there is square of deviation..... If we don't square and do directly root.... So my question is why we do square....?
Standard deviation: The 5 step process.
1. Figure out what the mean/average (will use the word mean going forward) is from the given data set.
2. Subtract each entity in the data set 'from the mean'
3. For each one of the resultant entities, apply square.
4. Add up the numbers and divide again by the total number of instances. (Figure out the mean one more time)
5. When you get the mean again, apply square root. --> And that's your 'standard deviation'
Important to note: There are two types of standard deviation --> libweb.surrey.ac.uk/library/skills/Number%20Skills%20Leicester/page_19.htm
So, for the entirety of the dataset you divide by the number of entities. For a sample dataset within a given dataset, --> Total number of entities minus 1. (See link)
Is 2.7 a lot, a little. I wish there was more definition given to the magnitude of the number. Also Google Sheets has STDEV() which is quicker
for your first example, where you get 1.58 for the standard deviation is this now 1 sigma or 2? Or in other words, how can you see or find out which standard deviation (that you calculate) is 1 sigma or 2?
Hello Mr. Anderson. I used to watch your videos when I was in intermediate around 6 years ago or maybe more than that. And now, after 6 years here I am again doing my MS n you saved me again. Thanks
I don’t understand why we include n-1 or n in the square root. I mean should we not first get the square root of the sum of squared residuals and then divide by n-1 or n.
Plz explain. Thx
According to the National Center for Health Statistics, the mean height of an American male is 69.3 inches and the mean height of an American female is 63.8 inches. The standard deviation for both genders is 2.7 inches.
YOU ROCK!!! Thank you for posting this!! THANK YOU!!
Well, actually if average is 5' 9'' is doesn't mean that "most men are 5' 9''. It's a common mistake. Of course in ideal normal distribution it is true but it shouldn't be said as '...it means...'
Finally a teacher with some common fucking sense. Why, in this day and age, would anyone do this shit by hand? What a pathetic waste of the technology we have. Most of us aren't trying to become physicists so really it is illogical to NOT use the tools available.
Fml This so hard
I hate math just trynna get bachelors 😫😫😫 fuck that I'm gonna stripper lol
wth do you mean "something like 1.58"? I am confused dude, how is 2.5^2 =to "1.58"
Thank you SO SO much... This video might have saved me from summer school...
I've been a fan of yours since I've started taking classes online! I think they would benefit from referring podcasts like yours to guide us through our online learning experience! You should try it! I'm in my fourth week and NOW I finally understand how to do standard deviations... Pretty sad on my end, but kudos to you for the AMAZING learning lessons. Not to mention their short, easy, and funny! :o) THANK YOU!!
Yeah i wish my professors would be like this, because I got Chinese lady which I don't even know what she's saying half of the time and when I do it all sounds crazy.
What does it mean to have 68% of individuals in first standard deviation and 95% if the Individuals are in the second standard deviation. That doesn't equal to 100%. How is that explained?
A standard deviation of laboratory results gives us the uncertainty in the analysis. The students all determine the density of a block of wood, but they get different numbers. The standard deviation of the different numbers tells us the error in the analysis. The standard deviation of the heights of the boys? Why would anyone be interested. With calculators, the mechanics of standard deviation seems irrelevant. (I make videos, but yours are better)
You need to correct the part where you've written -2 sq = 4 unless you put (-2) sq in brackets, the answer will be -4
You apparently suffer from a condition called Pentaphobia, the fear of saying the number 5 :)
Thank you! My professor in grad school assigned your video for an assignment and this was a topic I was REALLY struggling with even after having a course of research and statistics >.< thanks to your video I feel so much more confident going forward in interpreting data
I know that the formula gives the correct result and hence the formula is correct, but I do not understand why we have to subtract 1 from N in the denominator? Why is that exactly?
plz help I have run into a problem when adding the data points and dividing by the number of data points in a different sequence of numbers I receive a decimal number which does not allow me to accurately calculate tge variance? when doing standard deviation what happens if whole numbers divide to a decimal?
Why n-1. Some book writen that (×-×)2 / n. But u and some authors stated that n-1 also.
Well you just made this not scary anymore! THANK YOU!!!!!!!!
Thank you for explaining it in logical terms. I am a non-traditional student taking a college stats class and haven't done any calculations in 30 years, and the textbook is not clear at all.
Where were you when I was in high school? Great Video!
Math is hard for me. Because I have to make the connections whereas in other subjects there’s context to lead to a straight answer . Math has multiple steps and if there’s a wrong one you get a complete different answer
It's annoying when lecturers do not use universal mathematical terms, because standar deviation is sigma, but not s
King I’m watching this for my AP bio class and I just know I’m gonna pass it bc of this😋
Okay so we now know how to get one result called a standard deviation. So how does one get a standard deviation 2 from a formula that can only produce one result given a set?
Thank you so much!!! My chem teacher never explained how to use this formula in class!
you didn't say how to calculate the SD in the first half of the video, and you didn't say what the SD showed in the second.
FINALLY I UNDERSTAND THIS!!!
yeah but what the heck is the number we get? Is that the the number of inches above and below 5'9"?
oh my goodness. I've spent so much time trying to understand this concept and Mr Andersen explains it in exactly one minute and eleven seconds. Kudos to you Mr Andersen. Give this man a gold star.
Im kinda sad that I got 3.39. Update I subtracted wrong and I fixed it.
I understand the concept degrees of freedom, but why does it apply to the standard deviation?
Thanks for the reply but I wrote the equation like this
(Std. Dev)^2 = (Summation of (X - mean)^2) divided by n
notice the square at the (Std. Dev) so it's the same as
(Std. Dev) = Square Root (Summation of (X - mean)^2) divided by n
so the only difference is by dividing by (n-1) we get more accurate result than by n?
Hey 197syahnur, what you actually have there is the VARIANCE not the standard deviation. Not only that but you're working with the Variance of a Population rather than a sample. The differences is that, when you have a sample, dividing by n-1 gives a better estimate (you just have to trust me on this!) Std. Dev = Square Root ((Summation of (x - mean)^2) divided by n-1).
hey dude, there are different ways of writing out the formula. One of many factors being, sometimes the numbers that you have been given to work with are a sample of more numbers and if that is the case the formula will be written differently to a question that has the WHOLE population of numbers instead of a sample. :) You should use the exact same working for both of them.
hey dude, there are different ways of writing out the formula. One of many factors being, sometimes the numbers that you have been given to work with are a sample of more numbers and if that is the case the formula will be written differently to a question that has the WHOLE population of numbers instead of a sample. :) You should use the exact same working for both of them.
This helped alot but I have todo this with 30 numbers and each come out to like 5000 fml
thank you so much.
yeah I got it right !!
but we didn't learn about SD in epidemiology we learn how to use the graph
just so you know. you were wrong in saying 5 foot 9 is the average/mean. it is in fact the median.