Standard Deviation Around an Arbitrary MeanMotivation behind standard deviation?Variance and Standard Deviation of multiple dice rollsRelationships between mean and standard deviation when one variable is linear function of anotherStandard deviation with exponential distributionstandard deviation probability of a poission distributionStandard deviation and probability in a problemStandard Deviation Divided by Errorintepretation of standard deviation for geometric mean$n$ vs $n-1$ for the standard deviationCalculating the standard deviation of a distribution around a varying mean

Different outputs for `w`, `who`, `whoami` and `id`

As a new Ubuntu desktop 18.04 LTS user, do I need to use ufw for a firewall or is iptables sufficient?

Is a party consisting of only a bard, a cleric, and a warlock functional long-term?

Does .bashrc contain syntax errors?

New passport but visa is in old (lost) passport

Aluminum electrolytic or ceramic capacitors for linear regulator input and output?

What is the meaning of まっちろけ?

Print a physical multiplication table

When to use a slotted vs. solid turner?

Math equation in non italic font

Why do newer 737s use two different styles of split winglets?

Could the Saturn V actually have launched astronauts around Venus?

Is it insecure to send a password in a `curl` command?

How could a scammer know the apps on my phone / iTunes account?

What's the meaning of a knight fighting a snail in medieval book illustrations?

Are all passive ability checks floors for active ability checks?

Is honey really a supersaturated solution? Does heating to un-crystalize redissolve it or melt it?

What did “the good wine” (τὸν καλὸν οἶνον) mean in John 2:10?

ERC721: How to get the owned tokens of an address

Is it ever recommended to use mean/multiple imputation when using tree-based predictive models?

Custom alignment for GeoMarkers

Fastest way to pop N items from a large dict

Professor being mistaken for a grad student

Relationship between sampajanna definitions in SN 47.2 and SN 47.35



Standard Deviation Around an Arbitrary Mean


Motivation behind standard deviation?Variance and Standard Deviation of multiple dice rollsRelationships between mean and standard deviation when one variable is linear function of anotherStandard deviation with exponential distributionstandard deviation probability of a poission distributionStandard deviation and probability in a problemStandard Deviation Divided by Errorintepretation of standard deviation for geometric mean$n$ vs $n-1$ for the standard deviationCalculating the standard deviation of a distribution around a varying mean













1












$begingroup$


I'm collecting data from x and y axis offset from origin of the impact points of rounds I've shot at a target, and I've calculated my standard deviations in the x and y directions as $ sigma_x $ and $ sigma_y $ respectively from their variances, and I have also calculated the standard deviation of the root of the sums of their squares (the magnitude of the distance from the origin/bull's eye) as $sigma_r$. Now I know that these values are deviations around the mean value of each variable, which characterizes my shot grouping. I'm seeking to find my standard deviation away from the origin as well, i.e. I'm wanting to know how far I'm deviating away from the center of the target versus how far I'm deviating from the calculated center of my grouping. Would this value just be the calculation of the $sigma^2$ and $sigma$ around a mean of 0 in all the variables so that I have a measure of deviation from perfect, or is this the incorrect way to go about the problem. All standard deviations used are population standard deviations, e.g. $$ sigma^2 = sum_i=1^n left ( frac1n(x_i - mu)^2 right ) ;; ; ; ; sigma = sqrtsigma^2 $$ where in the case in question, $mu$ would be taken to be 0, leaving just the sums of the squares as the variance.










share|cite|improve this question









$endgroup$











  • $begingroup$
    You seem to be interested in the two second moments about the origin, an important notion, though closely related to variance.
    $endgroup$
    – André Nicolas
    Nov 9 '14 at 6:17










  • $begingroup$
    I believe what I'm asking is if I have the correct idea for the calculation of the second moment about the origin.
    $endgroup$
    – Doryan Miller
    Nov 9 '14 at 6:24










  • $begingroup$
    Yes, it is right.
    $endgroup$
    – André Nicolas
    Nov 9 '14 at 6:26










  • $begingroup$
    Note the formula $E(X^2) = Var(X) + mu^2$, so you don't need to do a whole new calculation if you already know $mu$ and $sigma_x$.
    $endgroup$
    – user187373
    Nov 9 '14 at 7:49










  • $begingroup$
    If I'm reading that correctly, what I'm really just searching for, going by the name of the second moment around the origin, is merely the expected value of the square of my data, which is the first raw moment around the mean plus the square of said mean?
    $endgroup$
    – Doryan Miller
    Nov 9 '14 at 15:17















1












$begingroup$


I'm collecting data from x and y axis offset from origin of the impact points of rounds I've shot at a target, and I've calculated my standard deviations in the x and y directions as $ sigma_x $ and $ sigma_y $ respectively from their variances, and I have also calculated the standard deviation of the root of the sums of their squares (the magnitude of the distance from the origin/bull's eye) as $sigma_r$. Now I know that these values are deviations around the mean value of each variable, which characterizes my shot grouping. I'm seeking to find my standard deviation away from the origin as well, i.e. I'm wanting to know how far I'm deviating away from the center of the target versus how far I'm deviating from the calculated center of my grouping. Would this value just be the calculation of the $sigma^2$ and $sigma$ around a mean of 0 in all the variables so that I have a measure of deviation from perfect, or is this the incorrect way to go about the problem. All standard deviations used are population standard deviations, e.g. $$ sigma^2 = sum_i=1^n left ( frac1n(x_i - mu)^2 right ) ;; ; ; ; sigma = sqrtsigma^2 $$ where in the case in question, $mu$ would be taken to be 0, leaving just the sums of the squares as the variance.










share|cite|improve this question









$endgroup$











  • $begingroup$
    You seem to be interested in the two second moments about the origin, an important notion, though closely related to variance.
    $endgroup$
    – André Nicolas
    Nov 9 '14 at 6:17










  • $begingroup$
    I believe what I'm asking is if I have the correct idea for the calculation of the second moment about the origin.
    $endgroup$
    – Doryan Miller
    Nov 9 '14 at 6:24










  • $begingroup$
    Yes, it is right.
    $endgroup$
    – André Nicolas
    Nov 9 '14 at 6:26










  • $begingroup$
    Note the formula $E(X^2) = Var(X) + mu^2$, so you don't need to do a whole new calculation if you already know $mu$ and $sigma_x$.
    $endgroup$
    – user187373
    Nov 9 '14 at 7:49










  • $begingroup$
    If I'm reading that correctly, what I'm really just searching for, going by the name of the second moment around the origin, is merely the expected value of the square of my data, which is the first raw moment around the mean plus the square of said mean?
    $endgroup$
    – Doryan Miller
    Nov 9 '14 at 15:17













1












1








1





$begingroup$


I'm collecting data from x and y axis offset from origin of the impact points of rounds I've shot at a target, and I've calculated my standard deviations in the x and y directions as $ sigma_x $ and $ sigma_y $ respectively from their variances, and I have also calculated the standard deviation of the root of the sums of their squares (the magnitude of the distance from the origin/bull's eye) as $sigma_r$. Now I know that these values are deviations around the mean value of each variable, which characterizes my shot grouping. I'm seeking to find my standard deviation away from the origin as well, i.e. I'm wanting to know how far I'm deviating away from the center of the target versus how far I'm deviating from the calculated center of my grouping. Would this value just be the calculation of the $sigma^2$ and $sigma$ around a mean of 0 in all the variables so that I have a measure of deviation from perfect, or is this the incorrect way to go about the problem. All standard deviations used are population standard deviations, e.g. $$ sigma^2 = sum_i=1^n left ( frac1n(x_i - mu)^2 right ) ;; ; ; ; sigma = sqrtsigma^2 $$ where in the case in question, $mu$ would be taken to be 0, leaving just the sums of the squares as the variance.










share|cite|improve this question









$endgroup$




I'm collecting data from x and y axis offset from origin of the impact points of rounds I've shot at a target, and I've calculated my standard deviations in the x and y directions as $ sigma_x $ and $ sigma_y $ respectively from their variances, and I have also calculated the standard deviation of the root of the sums of their squares (the magnitude of the distance from the origin/bull's eye) as $sigma_r$. Now I know that these values are deviations around the mean value of each variable, which characterizes my shot grouping. I'm seeking to find my standard deviation away from the origin as well, i.e. I'm wanting to know how far I'm deviating away from the center of the target versus how far I'm deviating from the calculated center of my grouping. Would this value just be the calculation of the $sigma^2$ and $sigma$ around a mean of 0 in all the variables so that I have a measure of deviation from perfect, or is this the incorrect way to go about the problem. All standard deviations used are population standard deviations, e.g. $$ sigma^2 = sum_i=1^n left ( frac1n(x_i - mu)^2 right ) ;; ; ; ; sigma = sqrtsigma^2 $$ where in the case in question, $mu$ would be taken to be 0, leaving just the sums of the squares as the variance.







statistics






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Nov 9 '14 at 6:12









Doryan MillerDoryan Miller

263112




263112











  • $begingroup$
    You seem to be interested in the two second moments about the origin, an important notion, though closely related to variance.
    $endgroup$
    – André Nicolas
    Nov 9 '14 at 6:17










  • $begingroup$
    I believe what I'm asking is if I have the correct idea for the calculation of the second moment about the origin.
    $endgroup$
    – Doryan Miller
    Nov 9 '14 at 6:24










  • $begingroup$
    Yes, it is right.
    $endgroup$
    – André Nicolas
    Nov 9 '14 at 6:26










  • $begingroup$
    Note the formula $E(X^2) = Var(X) + mu^2$, so you don't need to do a whole new calculation if you already know $mu$ and $sigma_x$.
    $endgroup$
    – user187373
    Nov 9 '14 at 7:49










  • $begingroup$
    If I'm reading that correctly, what I'm really just searching for, going by the name of the second moment around the origin, is merely the expected value of the square of my data, which is the first raw moment around the mean plus the square of said mean?
    $endgroup$
    – Doryan Miller
    Nov 9 '14 at 15:17
















  • $begingroup$
    You seem to be interested in the two second moments about the origin, an important notion, though closely related to variance.
    $endgroup$
    – André Nicolas
    Nov 9 '14 at 6:17










  • $begingroup$
    I believe what I'm asking is if I have the correct idea for the calculation of the second moment about the origin.
    $endgroup$
    – Doryan Miller
    Nov 9 '14 at 6:24










  • $begingroup$
    Yes, it is right.
    $endgroup$
    – André Nicolas
    Nov 9 '14 at 6:26










  • $begingroup$
    Note the formula $E(X^2) = Var(X) + mu^2$, so you don't need to do a whole new calculation if you already know $mu$ and $sigma_x$.
    $endgroup$
    – user187373
    Nov 9 '14 at 7:49










  • $begingroup$
    If I'm reading that correctly, what I'm really just searching for, going by the name of the second moment around the origin, is merely the expected value of the square of my data, which is the first raw moment around the mean plus the square of said mean?
    $endgroup$
    – Doryan Miller
    Nov 9 '14 at 15:17















$begingroup$
You seem to be interested in the two second moments about the origin, an important notion, though closely related to variance.
$endgroup$
– André Nicolas
Nov 9 '14 at 6:17




$begingroup$
You seem to be interested in the two second moments about the origin, an important notion, though closely related to variance.
$endgroup$
– André Nicolas
Nov 9 '14 at 6:17












$begingroup$
I believe what I'm asking is if I have the correct idea for the calculation of the second moment about the origin.
$endgroup$
– Doryan Miller
Nov 9 '14 at 6:24




$begingroup$
I believe what I'm asking is if I have the correct idea for the calculation of the second moment about the origin.
$endgroup$
– Doryan Miller
Nov 9 '14 at 6:24












$begingroup$
Yes, it is right.
$endgroup$
– André Nicolas
Nov 9 '14 at 6:26




$begingroup$
Yes, it is right.
$endgroup$
– André Nicolas
Nov 9 '14 at 6:26












$begingroup$
Note the formula $E(X^2) = Var(X) + mu^2$, so you don't need to do a whole new calculation if you already know $mu$ and $sigma_x$.
$endgroup$
– user187373
Nov 9 '14 at 7:49




$begingroup$
Note the formula $E(X^2) = Var(X) + mu^2$, so you don't need to do a whole new calculation if you already know $mu$ and $sigma_x$.
$endgroup$
– user187373
Nov 9 '14 at 7:49












$begingroup$
If I'm reading that correctly, what I'm really just searching for, going by the name of the second moment around the origin, is merely the expected value of the square of my data, which is the first raw moment around the mean plus the square of said mean?
$endgroup$
– Doryan Miller
Nov 9 '14 at 15:17




$begingroup$
If I'm reading that correctly, what I'm really just searching for, going by the name of the second moment around the origin, is merely the expected value of the square of my data, which is the first raw moment around the mean plus the square of said mean?
$endgroup$
– Doryan Miller
Nov 9 '14 at 15:17










1 Answer
1






active

oldest

votes


















0












$begingroup$

The line of reasoning in the question is correct.



Calculation of moments about the origin differ only from the former by setting $mu = 0$.






share|cite|improve this answer









$endgroup$












    Your Answer





    StackExchange.ifUsing("editor", function ()
    return StackExchange.using("mathjaxEditing", function ()
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    );
    );
    , "mathjax-editing");

    StackExchange.ready(function()
    var channelOptions =
    tags: "".split(" "),
    id: "69"
    ;
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function()
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled)
    StackExchange.using("snippets", function()
    createEditor();
    );

    else
    createEditor();

    );

    function createEditor()
    StackExchange.prepareEditor(
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader:
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    ,
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    );



    );













    draft saved

    draft discarded


















    StackExchange.ready(
    function ()
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f1012927%2fstandard-deviation-around-an-arbitrary-mean%23new-answer', 'question_page');

    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    0












    $begingroup$

    The line of reasoning in the question is correct.



    Calculation of moments about the origin differ only from the former by setting $mu = 0$.






    share|cite|improve this answer









    $endgroup$

















      0












      $begingroup$

      The line of reasoning in the question is correct.



      Calculation of moments about the origin differ only from the former by setting $mu = 0$.






      share|cite|improve this answer









      $endgroup$















        0












        0








        0





        $begingroup$

        The line of reasoning in the question is correct.



        Calculation of moments about the origin differ only from the former by setting $mu = 0$.






        share|cite|improve this answer









        $endgroup$



        The line of reasoning in the question is correct.



        Calculation of moments about the origin differ only from the former by setting $mu = 0$.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Mar 12 at 10:51









        Doryan MillerDoryan Miller

        263112




        263112



























            draft saved

            draft discarded
















































            Thanks for contributing an answer to Mathematics Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid


            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.

            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function ()
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f1012927%2fstandard-deviation-around-an-arbitrary-mean%23new-answer', 'question_page');

            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            How should I support this large drywall patch? Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern) Announcing the arrival of Valued Associate #679: Cesar Manara Unicorn Meta Zoo #1: Why another podcast?How do I cover large gaps in drywall?How do I keep drywall around a patch from crumbling?Can I glue a second layer of drywall?How to patch long strip on drywall?Large drywall patch: how to avoid bulging seams?Drywall Mesh Patch vs. Bulge? To remove or not to remove?How to fix this drywall job?Prep drywall before backsplashWhat's the best way to fix this horrible drywall patch job?Drywall patching using 3M Patch Plus Primer

            random experiment with two different functions on unit interval Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 23, 2019 at 00:00UTC (8:00pm US/Eastern)Random variable and probability space notionsRandom Walk with EdgesFinding functions where the increase over a random interval is Poisson distributedNumber of days until dayCan an observed event in fact be of zero probability?Unit random processmodels of coins and uniform distributionHow to get the number of successes given $n$ trials , probability $P$ and a random variable $X$Absorbing Markov chain in a computer. Is “almost every” turned into always convergence in computer executions?Stopped random walk is not uniformly integrable

            Lowndes Grove History Architecture References Navigation menu32°48′6″N 79°57′58″W / 32.80167°N 79.96611°W / 32.80167; -79.9661132°48′6″N 79°57′58″W / 32.80167°N 79.96611°W / 32.80167; -79.9661178002500"National Register Information System"Historic houses of South Carolina"Lowndes Grove""+32° 48' 6.00", −79° 57' 58.00""Lowndes Grove, Charleston County (260 St. Margaret St., Charleston)""Lowndes Grove"The Charleston ExpositionIt Happened in South Carolina"Lowndes Grove (House), Saint Margaret Street & Sixth Avenue, Charleston, Charleston County, SC(Photographs)"Plantations of the Carolina Low Countrye