Standard Definition and 1000 Threads

Going through my notes ... and I see the following: 1. Variance = ##\displaystyle \text{Var(X)} = \sigma^2 = \frac{1}{n - 1} \sum_i = 1 ^n \left(x_i - \overline x \right)^2## 2. Standard Deviation = ##\sigma = \sqrt {Var(X)} = \sqrt {\sigma^2}## Both variance and standard deviation are...

I tried some workings but got me nowhere. I just want to ask whether this question is solvable, i.e the answer can be in numerical value. If yes, then I want to try a bit by myself before asking for hint here. Thanks

What is the standard error of the coefficient of variation in an exponential distribution?

In the textbook Electrochemical Systems by Newman and Alyea, chapter 14: The definition of some thermodynamic functions, chemical potential of component (ionic or neutral) is written as a function of absolute activity: $$ \mu_i = RTln(\lambda_i) \tag {1} $$ where ##\lambda_i## is the absolute...

I did some research online and found that "When certain elementary particles move through a magnetic field, they are deflected in a manner that suggests they have the properties of little magnets." To explain this phenomenon, physicists invented the concept of spin. So far so good. What I...

I started by expanding ##dx## and ##dt## using chain rule: $$dt = \frac{dt}{dX}dX+\frac{dt}{dT}dT$$ $$dx = \frac{dx}{dX}dX+\frac{dx}{dT}dT$$ and then expressing ##ds^2## as such: $$ds^2 =...

This is the question; This is the solution as received; I am not familiar with the approach used in the solution...my thinking was as follows The frequencies are the same...the only thing changing are the discrete variables thus; Let ##[x= 2,4,6]## and ##[y=7,13,19]## form a...

I don’t get how they got the equation for the standard deviation. Why do they only square with the time in the denominator? Thanks!

Assuming the Sun’s core has a mass of 0.35 Msolar_mass and taking values for other quantities from a internet background search or from the following figures (i.e.: Radius "solar core" = 0.25 Rsolar_radius ): ------------------------------------------------------------------------...

Using this error propagation formula: I expressed the standard deviation (s) and the partial derivatives of s w.r.t. each data point as: This gives me an uncertainty of: , where m is the mean. Does this seem reasonable for the uncertainty of the standard deviation? I also found the thread...

Is the Standard Model overfitted? I hear that the standard model is the most accurate model that we have so far showing accuracy of 13 digits or so. However I am wondering if this accuracy comes from adding so many constants until it fits. First of all the standard model takes in 25 constants...

Hello everyone, Our topology professor have introduced the standard topology of ##\mathbb{R}## as: $$\tau=\left\{u\subset\mathbb{R}:\forall x\in u\exists\delta>0\ s.t.\ \left(x-\delta,x+\delta\right)\subset u\right\},$$ and the lower limit topology as...

Hi, I’ve read military EMC standard (such as MIL 461) requires peak detection while consumer standard requiers average detection. Does it mean the peak detection is stricter than the average one?

First I'll give some context about how the book's written as many books are presenting it in different ways. Reference: CRYPTOGRAPHY AND INFORMATION SECURITY, THIRD EDITION By PACHGHARE, V. K. Confusions: 1) Why is Expansion Permutation called so? The name sounds very contrary to what...

SR interpreted as having no absolute frame of reference and an absolute frame type version of SR, where the speed of light is isotropic only in one undetectable frame are considered equivalent, since they use the same math. But here is a scenario in which I don't see how the physical predictions...

Hello, I noticed while trying to calculate the stardart gravity acceleration of the Earth that I never arrived at the defined value of 9.80665 m/s2 no matter that I calculate it with the equatorial radius, the polar radius, mean radius or the average of the equatorial and polar radius. With what...

I know there are some stationary 3d scanners like this, but they are really expensive. When I saw, well an addition to handheld 3d scanner - a robotic hand, I came up with an Idea that same can be done with a simple camera, and photogrammetry. Found a nice article about photogrammetry on the...

If the standard model Lagrangian were generalized into what might be called "core capabilities" what would those capabilities be? For example, there are a lot of varying matrices involved in the standard model Lagrangian and we can generalize all of them as the "core capability" of matrix...

hi, i have studied Standard Model for particle physics - at present it is described by three groups - i have studied - these groups but could not establish what particular feature suggest of these group to be used to describe SM. Thanks

Hello, I watched MIT course on Nuclear physics (13. Practical Radiation Counting Experiments on ytb) and I do not understand why 2*sigma (standard deviation) = 0.05* countRate. As far as I know, integral of normal distribution from -2sigma to 2 sigma gives 95 % probability, but how can 2*sigma...

In Keisler Elementary Calculus page 39, example 4 it shows how to compute the standard parts of the following expression: Example 4: If ##\epsilon## is infinitesimal but non zero, find the standard part of ##b=\frac {\epsilon} {5-\sqrt{25+ε}}## Before calculating the standard parts the...

In a proof of a theorem or in mathematical writing generally, if there is a statement of a sub-theorem, does a proof always need to be given if 'obvious' or if obtained by inspection? Is there a way of saying "I got this by trying some numbers in a calculator and the pattern was clear"? The...

Reference: https://scitechdaily.com/breaking-cosmology-too-many-disk-galaxies-a-significant-discrepancy-between-prediction-and-reality/ The following are quotes from the reference. 1. The Standard Model of Cosmology describes how the universe came into being according to the view of most...

Is there a standard way to measure how far a system is displaced from equilibrium that can be applied to all physical systems? So, for example, a ball that is kicked, a spring that is stretched, a liquid that’s heated, and a charged battery are all systems that are displaced from equilibrium. I...

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.040403 In QM, I was taught that the imaginary unit ##i## in wave functions is merely a mathematical tool. It has no physical meaning. We can always take the real part of the complex wave functions. Therefore, there should be some...

Hi, I obtain really high standard deviations in Excitation-Emission Spectra mainly for the phenolic compounds in olive oil (Em: 290-350nm). Method: I weigh 0.05g of olive oil and dilute it up to 25ml with cyclohexane to remain in the range of linearity for absorbance measurements to correct...

Find the textbook problem here; Find the textbook solution here: Now, to my question, did the textbook guys make an error on the value of ##σ?##, see my working; Mean (##13## boys)=##\dfrac{153.4+(148.8×12)}{13}=149.15## We know that, ##29.16##=##\dfrac{\sum x^2}{12}##-##(148.8)^2## ##\sum...

In English, does the equation have any standard name besides (generalization of) the Euler-Lagrange Theorem? I have seen the designation "Euler-Poisson Equation" used by the Russian mathematician Lev Elsholtz way back in 1956 repeated in recent Russian webpages, but am not sure whether this...

Hi all - I wonder if you can help please. Watching a video on youtube to help me understand about the mean, variance and standard deviation but last part of video left me confused. The speaker said the following for the formula for standard deviation: Consider if the variance is 200 for the...

My solution in shown on the attached files. The overall reaction between Mn02 is 0.81 Volts The overall reaction which shows the reformation of the MnO2 catalyst is .27 Volts. The first reaction is more positive which shows that the MnO2 can work as a catalyst.

Hi! I'd like to ask you if my calculation of the amplitude on the mentioned process in the Standard Model is correct. The three diagrams contributing at lowest order should be where in the middle one the two Higgs boson are NOT forming a quartic interaction vertex. My attempt at calculating the...

b 90\% of the insects die after t hours. (i) Represent this information on a standard normal curve diagram, indicating clearly the area representing 90\% (ii) Find the value of \textbf{t}. $P(Z\le t) =0.9\quad Z = 1.282\quad t=57+(4.4(1.282))=62.64$ hours \begin{tikzpicture}[scale=0.6]...

Determine the following standard normal (z) curve areas: Determine the following standard normal (z) curve areas: a. The area under the z curve to the left of $1.75$ from table $5\ \textit{$z^{*}$} =1.7 \textit{ col } .05 = .9599$ $\textit{ \textbf{$W\vert A$} input }...

Does the S.E. of $38.72 mean, I sould expect to win or lose up to $77.4 (2x S.E), 95% of the time?

Here is the report submitted https://www.bbc.com/news/world-us-canada-57619755 "UFO report: US finds no explanation for sightings The US government has said it has no explanation for dozens of unidentified flying objects seen by military pilots. A Pentagon report released on Friday says of...

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Chapter 1, Section 1.2 Write the standard form of the equation of the circle with the given characteristics. 72. Center: (−2, −6); Solution point: (1, −10) Solution: given: Center: (−2, −6); => h=-2, k=-6 => then (x - (-2))^2 + (y - (-6))^2 = r^2 (x +2)^2 + (y +6)^2 = r^2... I then use...

Chapter 1, Section 1.2 Write the standard form of the equation of the circle with the given characteristics. 74. Endpoints of a diameter: (11, −5), (3, 15) I want to know if the following steps are correct for me to answer the above question. Steps: 1. Find the distance between the points...

The mean of some data was 21.2°C, the standard deviation was 2, and the standard error was 0.8. My textbook says that using one standard deviation, we would report the temperature of the substance as 21.2 ± 2°C, while using the standard error, the temperature would be reported as 21.2 ± 0.8°C...

A recurring topic in particle physics, is the possibility of a "desert" above the electroweak scale: no new physics (new particles, new forces) until the grand unification scale or the Planck scale. It's important to remember that the Higgs boson mass was correctly predicted three years in...

While I will not be showing the graph here, I am trying to dissect what the question even means. While I do understand that relative uncertainty can be found via the equation ##\frac{\sigma_A}{A}##, I do not understand how I can find the "relative uncertainty of SEM". Does anybody here have any...

Hello! I am taking a course on Electroweak & Strong Interactions (you could equally call it Standard Model I) and I find it absolutely fascinating! 😍 We studied how weak interactions violate parity, introduction to QCD, flavor physics (CKM matrix, CP violation, …) and neutrino physics...

Hello. Microphone is a simple device and its mechanism is also simple. The device converting sound waves into electrical energy is mic. But I am little curious about how microphone manufacturer company check their mics before selling? Means Can I test my mic at home using standard process? I...

In using scintillator or germanium energy sensors, certain radionuclides representing some definite line energies are used to calibrate the sensors. What technique or method is used to measure or determine the energies of these standards.

One of the distance measures in cosmology is angular diameter distance, that can be used to determine a distance to objects whose actual (spatial) size is known, i.e. standard rulers. Beside baryonic acoustic oscillations, do we know other objects (or maybe I should better say structures) that...

Hi, Several times I encounter the argument that there is a "problem" with the masses in the Standard Model that we try to "understand". From the one side, you have people who ask why the neutrino masses are so small, and from the other side they ask why the top quark mass is so large. The...

Hi, I'd like to integrate this function: $$ \int _0^ {\pi/2} 2 \sin(x) \cos(x) \sqrt {1+\sin^{2}(x) } dx $$. I think I should introduce some substitution but I'm not sure. How should I proceed?

The mean is easy to calculate: (x_m * 10 + y_m * 5) /15 = 5312 Which is correct. But when you're suppose to calculate the variance it's impossible. The values are squared so none of the equations will really help me..

I've slowly been writing a thread on octonions and particle physics, just to explain some facts in a self-contained way, with all the proofs. I don't know where this will lead. I'm certainly not presenting a theory of physics, much less advocating one. Mainly it's just fun. Octonions and...