Standard Definition and 1000 Threads

  1. B

    Root Mean Square Or Standard Deviation

    Hello, I've been trying to find online where I could calculate my grade based off a college curve. So the average grade on the test was a 63. The RMS is 16. I got a 86. So what will my grade curve to? This is out of 50 people. Also, the professor curves to a 70 (I think).
  2. C

    Gaussian distribution other than standard form

    what changes does there occur in the result of the gaussian distribution "integration e^-alpha*x^2 dx=sqrt(pi/alpha) if i substitute that x^2 with some (x-a)^2? then what should be the integral result ?
  3. S

    Standard Deviation of Averages

    I am measuring the thickness of many identically prepared objects. In order to obtain the most accurate value, I measure each object multiple times, in different locations, and average these values to get the average thickness of that object, along with the standard deviation. But I am really...
  4. N

    Interpretation of QED in the Standard Model

    Three related questions on which I could use some help: a] In another thread, Bill_k posted something like: "Electrons, being charged, could exchange energy by exchanging a virtual photon." ok, yet I thought electrons usually interacted via the EM field ['real' photons]... So how...
  5. C

    Calculating the standard deviation of the standard deviation

    I was wondering if anyone could help me with calculating the standard deviation of the standard deviation. What I mean by this is say for example I roll a dice 100 times and then calculate the mean and standard deviation from the results I collected. The results are not going to be exact because...
  6. G

    Standard deviation of series of trials

    Say we want to saw ten planks and we have two methods available - one is sawing them all at once, ensuring they're all exactly uniform length. The other method is sawing them individually. Either method has EV of 1m and a standard deviation of 0.005m. I want to find the standard deviation of...
  7. M

    Beyond the noncommutative standard model

    http://arxiv.org/abs/1304.8050 Beyond the Spectral Standard Model: Emergence of Pati-Salam Unification Ali H. Chamseddine, Alain Connes, Walter D. van Suijlekom (Submitted on 30 Apr 2013) I have a few questions about this paper... How good is "almost uniquely"? i.e. it would be good to see...
  8. caffeinemachine

    MHB A Very Standard Theorem in Set Theory

    Let $A$ be any set. Show that there is no bijection between $A$ and the power set $\mathcal P(A)$ of $A$. (The power set of a set is the set of all its subsets including the empty-set.)
  9. C

    Length of Standard Flat Key to Prevent Failure

    Homework Statement Hi all, I have a question about a standard flat key being specified to prevent failure. I'm just quickly giving a problem description because once I understand what's going on I can easily run calculations but I'm missing something fundamental. Essentially the problem I...
  10. T

    How to use standard reduction potential table

    Hi, can someone please explain to me how I can identify which is the oxidation half and which is the reduction half of a redox reaction. I have read on the internet that the oxidation half is the highest up the table between the two then why doesn't it work for: (Ca^2+) + 2Br → Ca + Br2...
  11. C

    Converting scientific notation to standard digit numbers

    Homework Statement I'm trying to convert something like 1.25^-03 into it's standard number composed of standard decimals using a calculator (0.0125) - if you know what I mean. Thanks.
  12. marcus

    What Are the Possible Strategies for the Game of Single-Shot Work Extraction?

    So one can even have "beyond standard Thermodynamics" :biggrin: I just came across this and it seems interesting. http://arxiv.org/abs/1207.0434 Laws of thermodynamics beyond the von Neumann regime Dario Egloff, Oscar C. O. Dahlsten, Renato Renner, Vlatko Vedral (Submitted on 2 Jul 2012)...
  13. E

    Electrostatics - probably a standard question

    Q) A solid non-conducting sphere of radius R carries non-uniform charge distribution with charge density ρ = ρs(r/R), where ρs is a constant. Show that (a) the total charge on the sphere is Q = ∏ρsR3, and (b) find the electric field inside the sphere. Now first part (a) is fairly easy, assumed...
  14. B

    Higgs, neutrinos, and standard model status

    I've always understood that the "formula" for the Standard Model is SU(3) × SU(2) × U(1). Since the discovery of the Higgs boson, and observations of neutrino flavor oscillations, has that formula been revised, or is it still the same?
  15. B

    What Is the Correct Symbol for Gibbs' Energy Under Standard Conditions?

    My thermodynamics textbook says that chemical potential can take any of the following symbols: μ (condition-dependent), μ∇ (standard), μΘ (standard) (superscript plimsoll line) and μO (standard), with which one of the latter 3 being used depending on the temperature chosen to define standard...
  16. P

    How to Make a Standard Additions Curve?

    Hello, I am wondering how to make a standard additions curve for this experiment. In this experiment, we used cyclic voltammetry to determine the original concentration of an elixir. We diluted the elixir to 0.75mM based on a claimed concentration of acetaminophen (instructed) and an elixir...
  17. M

    Linear algebra; find the standard matrix representation

    Homework Statement Find the standard matrix representation for each of the following linear operators: L is the linear operator that reflects each vector x in R2 about the x1 axis and then rotates it 90° in the counterclockwise direction. Homework Equations The Attempt at a Solution So my...
  18. T

    How big is the standard model?

    How many internal degrees of freedom does it have? In other words, how many 4d real functions do we have to specify in configuration space (i mean the space we use in Path integration) in order to specify a state? It is difficult to state the question, so, in order to be more precise, the...
  19. B

    Standard deviation with frequency

    How do I work out the standard deviation of a set of variables where the frequency changes by a certain factor each time, but where there is no limit on the number of variables? Let's just use "test scores" as an example because that's easy to understand. The average is 80; 1 in 5 people...
  20. J

    Question about the number of particles in the standard model.

    Hi, I was just wondering why there are a finite number of fundamental particles in the universe. Why is it that when cern collide particles, the same particles are formed every time. Its like putting a hammer to a concrete block and every time you do so, the same chips with the same shape and...
  21. S

    Standard TTL 2-input NAND gate - open-collector/totem pole outputs

    Homework Statement Question: Refer to Fig. 6-5. This standard TTL 2-input NAND gate uses ______ (open-collector, totem pole) outputs. Solution: The 2-input TTL NAND gate in Fig. 6-5 (which is attached as "TheFigure.jpg") uses a totem pole output configuration. Homework Equations N/A...
  22. N

    Would a Universe be considered part of the standard model?

    From my basic understanding of the standard model it tries to identify the different kinds of particles, understand their functions and their subsequent sub atomic particles. But as particles and forces break down into smaller components, do they also build up into bigger components? For...
  23. M

    Standard enthelpy of formation of carbon gas

    Hi, The standard enthalpy of formation of carbon gas or C(g) is the enthalpy change for the formation of 1 mole of carbon gas from its elements in their reference form which for carbon (I believe) is C(graphite). Now I find the following standard enthalpy of formation for carbon gas / C(g)...
  24. O

    Explain how do we get standard error.

    Homework Statement I know that standard error is to calculate how the sample deviate from the population. But standard deviation divide √n ,then will get it. And I don't understand why there is a T/n from the picture I uploaded. Please help Homework Equations Standard error x sqrt(n)...
  25. T

    MHB How Can You Prove Standard Limits Without Using L'Hopital's Rule?

    I have a few questions for my homework assignments for solving limits, but in order to do those questions I have to use a few standard limits that we haven't been taught, which means I'll have to prove them. I know these can be done using L'Hopital's rule, but we haven't covered that yet so I...
  26. R

    Any recommendations for books or articles on the Standard Model?

    I'm an undergrad physics student and have to write an essay on the Higgs boson and the future of the standard model. I don't need to have a comprehensive understanding of the maths underpinning it all, but it's quite difficult to find any undergraduate level reading on the subject. I'm currently...
  27. N

    Finding Concentration of a Standard Solution using % purity ?

    Homework Statement I need to know the concentration in ppm of a standard Fe2+ solution. (diluted) Here is the data I have. I have 0.1964 g of Fe solution the purity is 99.7% The original solution was the above # of g in 250ml water. 10ml of this was then pipetted into a 100ml volumetric flask...
  28. X

    Finding the Standard Matrix A of a Linear Transformation T

    Homework Statement Let T be a linear transformation from R3 to R3. Suppose T transforms (1,1,0) ,(1,0,1) and (0,1,1) to (1,1,1) (0,1,3) and (3,4,0) respectively. Find the standard matrix of T and determine whether T is one to one and if T is onto Homework Equations The Attempt...
  29. X

    How Do You Find the Standard Matrix of a Linear Transformation?

    Homework Statement Let T be a linear transformation from R3 to R3. Suppose T transforms (1,1,0) ,(1,0,1) and (0,1,1) to (1,1,1) (0,1,3) and (3,4,0) respectively. Find the standard matrix of T and determine whether T is one to one and if T is onto Homework Equations The Attempt...
  30. X

    Linear Algebra Find the Standard Matrix of T

    Homework Statement Let T be a linear transformation from R3 to R3. Suppose T transforms (1,1,0) ,(1,0,1) and (0,1,1) to (1,1,1) (0,1,3) and (3,4,0) respectively. Find the standard matrix of T and determine whether T is one to one and if T is onto
  31. J

    Statistics Question - Find Standard Deviation of 5 numbers but only 4 given.

    For a sample of size 5, if x1 - x̄ = -5, x2 - x̄ = 9, x3 - x̄ = -7, and x4 - x̄ = -2, then the sample standard deviation is: Choose one answer. a. 5.639 b. 6.782 c. None of the other answers are correct d. 6.305 e. 6.066 Please note that x̄ is x-bar (mean of sample). This...
  32. F

    Standard Deviation in terms of Probability Function

    Homework Statement I've still yet to learn Latex since I'm pretty good with words equation editor, so here's the question typed out in words. Homework Equations I really don't know what to do here. The Attempt at a Solution
  33. C

    Why won't standard curve length function work in semi-circle?

    Ok, so for a give function f(x) it's curve length from a to b is supposed to be ∫(1+(f '(x))^2)dx evaluated from a to b. However even wolfram alpha had a hard time solving that, plus the results were wrong. What am I missing? PS: With f(x)= sqrt(r^2-x^2)
  34. G

    Transformed Standard Deviation?

    I realize you can transform the data in many ways, but I really can't find a method to solve this particular scenario anywhere online: Suppose you are given the mean and standard deviation of a set of data. Further suppose you take away (get rid of) "x" elements in the original data set, and...
  35. M

    Neutrino Minimal Standard Model

    Marcus suggested that the nuMSM deserves its own thread and I agree. The nuMSM is the context in which the Shaposhnikov-Wetterich prediction of the Higgs mass was made. (PF thread.) A search on "nuMSM" at InspireHEP turns up 29 papers, a lot of them about cosmology. Shaposhnikov in...
  36. Greg Bernhardt

    Particle Symmetry and the Standard Model by Matthew B. Robinson

    Author: Matthew B. Robinson Title: Symmetry and the Standard Model Amazon Link: https://www.amazon.com/dp/1441982663/?tag=pfamazon01-20 Prerequisities: Contents:
  37. D

    How to Rotate a Standard Cell to Align a Specific Plane with [001]?

    Hi, I have a standard cell which I would like to rotate. I would like to rotate it in such a way such that when I define some plane in the unrotated cell [hkl] that this same plane corresponds to the [001] plane in the rotated cell. I essentially want to keep the same unit cell, just rotate the...
  38. NanaToru

    Importance of a standard candle?

    So I'm a little confused about what a standard candle tells us exactly. From what I understand, it means that the luminosity is relatively constant. Does this tell me something about apparent or absolute magnitudes? Like if a supernova has a peak brightness of an apparent magnitude of 0.7, does...
  39. P

    MHB Find the standard form of conic

    Find the standard form of $7x^2+48xy-7y^2+20x-110y-50=0$ and find euclidean transformation taking it to standard form. Answer: matrix of coefficents has eigenvalues + or -25 with eigenvectors (4,3) and (3,-4) respectively. set x'=1/5(4x+3y+a) and y'=1/5(3x-4+b). then comparing the terms of...
  40. M

    MHB Equation of line in standard form

    I am having trouble with algebra... I have to write an equation in standard form containing the given point and having the give slope for (2,1);m=1 I have no clue what I am doing and am not able to find anything online. Please help
  41. H

    More than two standard deviations away from its mean

    more than "two standard deviations away from its mean" Suppose we need to find the probability that a binomial random variable with n = 100 and p = 0.5 is more than two standard deviations away from its mean and then compare this to the upper bound given by Chebyshev's Theorem. What is...
  42. marcus

    Conformal Standard Model (Meissner Nicolai) resonance at 325 GeV?

    Don't be fooled by the word "conformal". This is not "AdS/CFT" stuff. The math is not stringy. It is very largely the conventional standard model. They've found a way to extend it's applicability and make more radical changes unnecessary. Furthermore it's testable. Here's what Meissner and...
  43. J

    Rational roots - standard form of equation

    Hi everybody! I've hit a blank with regards to this 1 equation on a old exam paper - think I've overloaded myself a bit and just feel a bit like a airhead at the moment! I understand the actual method and getting to the answer but it starts off with a equation which you then need to get to...
  44. naima

    Is Hestenes massless electron beyond standard model?

    Hi all I just read Hestenes paper He has a massless electron which rotates about a fixed point at the speed of light . (look at eqns 8 9 10 and fig 1) I wonder if this is in the standard model or beyond? What is the lagragian of this "zitter" model?
  45. f95toli

    Estimating the standard deviation from sampled data

    I am en experimentalist and in most of my experiments I am interested in measuring the properties of distributions, i.e. the phenomenon I am measuring is stochastic and the parameters I am interested in are (in the simplest case) say the mean value and the width of the distribution (variance of...
  46. C

    Help Needed: Solving Sequences with Standard Limits Equations

    Homework Statement I'm having trouble with these here.. it's been a while since I've done sequences and I can't seem to make this work with Standard Limits equations. Clearly the answer given by Wolfram solver is there after the = but i'd like to know the reasoning behind it. Anyone that...
  47. S

    When standard deviation is undefined?

    Hi, I just solved a probability density function problem and the standard deviation is undefined.Does anyone know why it happens?It would help to develop my understanding.Thanks.
  48. B

    Conics/Rewriting Parabola into Standard Form

    25x^2-10x-200y-119=0 Should i divide both sides by 25 and then put y and constant to right side of equation and then complete the square?
  49. D

    Finding mass of glucose in standard solutions

    Homework Statement This is for an experiment that separates sugars in a sample using TLC. We are given a glucose standard solution with a concentration of 1mg/ml as well as 3 standard sugar solutions (glucose, fructose and maltose) all with the same concentration (10mg/ml) in 10% v/v...
  50. J

    Standard Matrix for an orthogonal projection transformation

    Let T:R^2 -> R^2 be the linear transformation that projects an R^2 vector (x,y) orthogonally onto (-2,4). Find the standard matrix for T. I understand how to find a standard transformation matrix, I just don't really know what it's asking for. Is the transformation just (x-2, y+4)? Any...
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