A community for students. Sign up today!
Here's the question you clicked on:
 0 viewing

This Question is Closed

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Suppose the average is 5 Individual observations, say one of them is 4

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3There are two types of deviations 1) Standard 2) Absolute

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Absolute deviation here \[\text{observation}\text{average or arithmetic mean}\] \[54=1\]

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0Absolute deviation is for a set of data elements, correct?

msumner
 one year ago
Best ResponseYou've already chosen the best response.2sorry I misspoke earlier. I meant Variance, not arithmetic mean

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3NP:) Standard deviation is the square root of variance

msumner
 one year ago
Best ResponseYou've already chosen the best response.2how about we establish a more concrete example?

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3@ParthKohli It's for individual element

msumner
 one year ago
Best ResponseYou've already chosen the best response.2I hope it is not too much to ask

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0But it's for an individual element from a set of elements, correct?

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Consider a population consisting of elements 2, 4, 4, 4, 5, 5, 7, 9 Let's find the mean first \[\frac{2+4+4+4+5+5+7+9}{8}=5\]

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Now, we'll find the difference of each data point from the mean and we'll square it \[(25)^2=9\]\[(45)^2=1\]\[(45)^2=1\]\[(45)^2=1\]\[(55)^2=0\]\[(55)^2=0\]\[(75)^2=4\]\[(95)^2=16\]

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0I think I have seen this on Wikipedia.

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Yes, I have taken the same example

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0So the variance is \(4\).

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Now, we need to find the average of these values That'll be the variance \[\frac{32}{8}=4\]

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Square root of this is standard deviation \[\sqrt 4=2\]

msumner
 one year ago
Best ResponseYou've already chosen the best response.2why do we square the differences?

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0Yup, can you tell me the formula for variance?

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0@msumner Because we must have a positive value, that's why.

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0Well... something along the lines of the above.

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3To find the absolute value of the difference, yes @ParthKohli is right

msumner
 one year ago
Best ResponseYou've already chosen the best response.2if the goal is to get an absolute value, why not just obtain the absolute value from the get go?

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0That is why statistics is pretty trivial.

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Yeah, then just take the absolute value of difference

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0Will we get the same answer?

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3We'll get Absolute deviation for individual element

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3(2−5)=3 (4−5)=1 (4−5)=1 (4−5)=1 (5−5)=0 (5−5)=0 (7−5)=2 (9−5)=4

msumner
 one year ago
Best ResponseYou've already chosen the best response.2I doubt we will get the same result consistently if we obtain the absolute value of the difference

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3@ParthKohli No, we won't get the same result Absolute deviation is defined for individual element, we won't take mean in this case

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.03 + 1 + 1 + 1 + 2 + 4 = 12

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Average of the absolute deviation is 12/8=1.5

msumner
 one year ago
Best ResponseYou've already chosen the best response.2is this the same concept as the distance between points?

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0Wow, I just got enlightenment.

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3@msumner do you get the insight?

msumner
 one year ago
Best ResponseYou've already chosen the best response.2Yes. How come there are two formulas for Standard Deviation?

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0This is somewhat like that.

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0Absolute deviation and standard deviation are different. T_T

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3That's average absolute deviation, the one we found earlier was standard deviation

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3What do you want to know?

msumner
 one year ago
Best ResponseYou've already chosen the best response.2why use a different formula when the population or set of elements are larger

msumner
 one year ago
Best ResponseYou've already chosen the best response.2I misspoke again. why use a different formula when the Sample is taken from a larger population?

msumner
 one year ago
Best ResponseYou've already chosen the best response.2I hope my questions are not a nuisance or troublesome!

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0You think your questions are nuisance? What... no!

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3I think standard deviation will provide a better insight of the variation of the sample,

msumner
 one year ago
Best ResponseYou've already chosen the best response.2I just turned 14 so bear with my amateur math questions :(

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0I am 13 and I have even more n00bish questions.

msumner
 one year ago
Best ResponseYou've already chosen the best response.2Here is what I am talking about

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Ok, I never knew this, thanks Let me find about these

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0http://en.wikipedia.org/wiki/Statistical_population and http://en.wikipedia.org/wiki/Statistical_sample

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0It says that a sample is a subset of population.

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3Population is used when we have data for all the population if we have data only for a sample of population, we use the sample standard deviation to guess estimate for the whole population

msumner
 one year ago
Best ResponseYou've already chosen the best response.2Hero do you know what ash is talking about?

ParthKohli
 one year ago
Best ResponseYou've already chosen the best response.0The population is the whole thing, and the sample is just the data collected from a small part of it.

msumner
 one year ago
Best ResponseYou've already chosen the best response.2@ParthKohli a Sample is said to be taken from a bigger population

msumner
 one year ago
Best ResponseYou've already chosen the best response.2draw then upload works!

msumner
 one year ago
Best ResponseYou've already chosen the best response.2now I get it. thank you!

ash2326
 one year ago
Best ResponseYou've already chosen the best response.3I should close it, shouldn't I?

msumner
 one year ago
Best ResponseYou've already chosen the best response.2yes, please. Thank you once again
Ask your own question
Ask a QuestionFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.