https://math.codidact.com/categories/41/tags/4013.rssNew Posts Tagged 'statistics' - MathematicsMathematics - Codidact2023-11-14T16:23:04Zhttps://math.codidact.com/posts/288906Is there a statistical method to identify the type of outliers shown in the pictures attached to my question?Ivan Nepomnyashchikhhttps://math.codidact.com/users/610182023-07-07T20:39:56Z2023-11-14T16:23:04Z<p>I have obtained experimental data:<img alt="Image_alt_text" src="https://math.codidact.com/uploads/aif2vdb9e66zqs137owlic7b9ik3"></p>
<p>Those "horns" (leftmost and rightmost peaks) in each ima...https://math.codidact.com/posts/289814What is the probability density function for the tau distribution?mr Tsjolderhttps://math.codidact.com/users/643002023-09-26T10:00:53Z2023-09-27T15:18:36Z<p>The <a href="https://en.wikipedia.org/wiki/Studentized_residual#Distribution">tau-distribution</a> is typically defined in terms of the <a href="https://en.wikipedia.org/wiki/Student%27s_t-distr...https://math.codidact.com/posts/289742Is it possible to show that a normalised random variable has zero mean and unit variance?mr Tsjolderhttps://math.codidact.com/users/643002023-09-19T15:19:37Z2023-09-19T15:20:14Z<p>Given some random variable $X_i$, is it possible to compute expectations of the normalised value, like: $$\mathbb{E}\biggl[\frac{X_i - \bar{x}}{s}\biggr],$$
where $\bar{x} = \frac{1}{N}\sum_{j=...https://math.codidact.com/posts/289643What is the formula for sample standard deviation of a small sample size?Ivan Nepomnyashchikhhttps://math.codidact.com/users/610182023-09-08T17:01:40Z2023-09-16T02:34:00Z<p>The formula for sample standard deviation is given by:</p>
$$s = \sqrt{\frac{\sum_{i=1}^{i=N} (x_i - \bar{x})^2}{N-1}}$$<p><strong>Am I right that when the sample size is small ($N<30$), the...https://math.codidact.com/posts/286527Notation for one-sided hypothesis testingtommihttps://math.codidact.com/users/534072022-05-30T11:36:06Z2023-08-26T06:39:06Z<p>I see the following notation for one-sided hypothesis testing:</p>
<ul>
<li>$H_0$: $K = 2$</li>
<li>$H_1$: $K > 2$</li>
</ul>
<p>I would find it more natural to write:</p>
<ul>
<li>$H_...https://math.codidact.com/posts/289325Is there a quadratic version of exponential smoothing?peterbalchhttps://math.codidact.com/users/647982023-08-10T10:44:19Z2023-08-10T10:44:19Z<p>I have a time series - let's say I'm given one new sample (a real value) every second.</p>
<p>I could take a moving average of the last 50
samples or I could use exponential smoothing of the s...https://math.codidact.com/posts/2881132 construals "of 100 patients presenting with a lump like the claimant’s in Gregg v Scott, 42 will be ‘cured’ if they are treated immediately."DNBhttps://math.codidact.com/users/536282023-05-10T07:08:27Z2023-05-13T01:07:29Z<p>Are there official terms for these 2 different interpretations of the same statistic?</p>
<blockquote>
<p>Lord Hoffmann and Baroness Hale advanced the following arguments against awarding
dam...https://math.codidact.com/posts/287642What is the Name of Function for Probability of a Certain Sum on Random Die Rolls?James McLellanhttps://math.codidact.com/users/567002022-12-28T21:30:29Z2022-12-29T02:30:54Z<p>Hi.</p>
<p>I'm writing a book about using statistics for roleplaying game design and am using this equation for calculating the probability of rolling a particular sum "n" on "z" throws of an "...https://math.codidact.com/posts/286004Sample skewness consistencyGuilherme Costahttps://math.codidact.com/users/534532022-02-22T10:55:44Z2022-03-04T08:54:25Z<p>Is sample skewness a consistent estimator of skewness?</p>
<!-- g: js, mdit -->https://math.codidact.com/posts/282737Probability of students given there are groupsPranav_M99https://math.codidact.com/users/541902021-07-21T16:12:05Z2021-11-02T14:53:19Z<p>A group of 60 second graders is to be randomly assigned to two classes of 30 each.
(The random assignment is ordered by the school district to ensure against any
bias.) Five of the second grad...https://math.codidact.com/posts/278558When and how should the $Z_n^2$ statistic be used?HDE 226868https://math.codidact.com/users/363722020-10-16T20:10:54Z2021-08-08T21:00:19Z<p>I was reading a paper (<a href="https://arxiv.org/abs/2010.06638">Kuechel et al. 2020</a>, since retracted; see <a href="https://arxiv.org/abs/2010.06638v1">original version</a>) claiming a dete...https://math.codidact.com/posts/280758In a SARIMA model, does the order in which I difference the time series matter?anoldmanintheseahttps://math.codidact.com/users/536472021-02-10T18:11:16Z2021-02-10T18:11:16Z<p>In a SARIMA model $\text{ARIMA}(p,d,q)\times(P,D,Q)_S$, we can write it as $$\Phi_P(B^S)\phi(B)(1-B^S)^D(1-B)^d x_t= \delta +\Theta_Q(B^S)\theta(B)w_t$$ where the capital letters are the paramet...https://math.codidact.com/posts/278553Which of the multiple definitions of correlation to use?Mithrandir24601https://math.codidact.com/users/81622020-10-16T16:21:29Z2020-10-17T15:32:48Z<p>In optics<sup class="footnote-ref"><a href="#fn1" id="fnref1">1</a></sup>, we have a notion of <a href="https://en.wikipedia.org/wiki/Degree_of_coherence#Degree_of_first-order_coherence">coheren...https://math.codidact.com/posts/278464Discrete data: Graphs and skewnessNezar https://math.codidact.com/users/534712020-10-11T13:49:32Z2020-10-15T10:49:47Z<p>I am studying an introductory course in statistic " Essentials of Statistics".
The author mentioned that Histograms are used to represent the frequency distribution of a contiuous data...