Statistics Definition and 998 Threads

  1. L

    How to Start a Problem I'm Struggling With

    I really don't know what to do for this problem. I looked at similar threads but couldn't seem to grasp the idea of it. I would like help on how to start.
  2. V

    MHB Creating An Awesome Statistics Course For Students

    Hi everybody, my name is Vaughny. I was once a statistics tutor, and I loved making statistics easier to understand for those who struggle learning the material. I've seen students in high school and college go through a painful experience of not having enough resources or just having horrible...
  3. S

    Question about hint given by the problem related to statistics

    I want to ask about the "problem-solving" box on the right. I don't understand why the class boundaries for the 16 - 25 group are 16 and 26. If I try to find it using my usual way, it will be 15.5 and 25.5 and the midpoint will be (15.5 + 25.5) / 2 = 20.5 Or if I use the hint "since age is...
  4. S

    MHB What is the probability of exceeding maximum weight with a normal distribution?

    The weight of goats at a farm is normally distributed with a mean of 60 kg and a standard deviation of 10 kg. A truck used to transport goats can only accommodate not more than 650 kg. If 10 goats are selected at random from the population, what is the probability that the total weight exceeds...
  5. Athenian

    Finding the Relative Uncertainty for the Standard Error of the Mean

    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...
  6. CPW

    Encouraging fact from cancer statistics

    We study cancer to get better at killing it. And here is an enouraging detail: Since 1975, the cancer death rate in the United States has decreased by 21.9% with a 15% decrease from 2007 to 2017. (https://seer.cancer.gov/csr/1975_2017)
  7. Dale

    Insights Posterior Predictive Distributions in Bayesian Statistics

    [url="https://www.physicsforums.com/insights/posterior-predictive-distributions-in-bayesian-statistics/"]Continue reading...
  8. C

    I Large Q^2 statistics at different colliders

    How tractable is it experimentally to measure deeply virtual compton scattering in bins of large Q^2, where Q^2 is the virtuality of the incoming photon, at e.g. Jefferson Lab which collides electron and proton? I know at LHC, colliding proton-proton, such processes would instead be statistics...
  9. D

    A Photon Statistics in QFT & String Theory

    In a given mode with an average number of photons ``##\bar{n}##, the photons are distributed around their average according to the formula $$p_n = e^{-\bar{n}} \frac{\bar{n}^n}{n!}$$ The justification of this formula in quantum field theory involves considering field operators acting on a...
  10. D

    Rotational partition function for CO2 molecule

    Hello fellow physicists, I need to calculate the rotational partition function for a CO2 molecule. I'm running into problems because I've found examples were they say this rotational partition function is: ##\zeta^r= \frac T {\sigma \theta_r} = \frac {2IkT} {\sigma \hbar^3}## Where...
  11. iVenky

    I What are the statistics of probability of dying today vs age?

    I don't intend to sound macabre, but I was having this thought if I have to quantify the probability of someone dying given his age (in days) how would I go about quantifying that with a minimal accuracy (ok if it's not accurate but I just need some number with days). Has anyone ever worked out...
  12. R

    What statistics services/platforms do you use that help you in life?

    I encountered a website with statistics for a large number of video games, specifically regarding their availability across various platforms, their sales over time and some other things and methods to visualize them I found this really helpful. Might there be other services like this that...
  13. E

    Python Online course for probability and statistics with emphasis on python

    I have been looking for a way to learn probability and statistics online and have searched but found nothing yet. I am looking for a course on probability and statistics that will not only teach me the basics but all there is to know about the subject. I would love it if the visualizations are...
  14. I

    B Different sample methods in statistics

    What is the difference between stratified and quota sampling of a population? For example, you can choose 200 males and 200 females from a state by quota sampling; or collect raw data first, stratify it, and then choose 200 males from one subsample and 200 females from the other subsample...
  15. G

    How Do I Calculate Confidence Intervals for Two Means?

    Here is the question I'm struggling with (Q1) : I just... I just don't understand what my first step is. Whats my barx1 and barx2? (bar x = mean, x1 = subscript 1) My thoughts on approaching this question : barX1 - barX2 `~ N(u1-u2, sd1^2/n1 + sd2^2/n2) Find Z value when p = 0.975, z = + or...
  16. G

    B Statistics Help : Hypothesis Testing

    Answer : I understnad why x(< or = ) 2 but I do not understand why we use 16 instead of 17 for the second range? When P(X>=16) > 0.005(which is the level of significance). Thank you for all the help given :)
  17. archaic

    Prob/Stats Introductory textbook for Probability and Statistics

    Hello! I'll be taking a probability and statistics course this semester. Does anyone know of any good textbook? I have access to an extensive catalogue of books on springer, so it would be extremely preferable for me if you could recommend something from there. Thanks.
  18. T

    Exploring the Grand Partition Function for an Einstein Solid

    $$Q_{(\alpha, \beta)} = \sum_{N=0}^{\infty} e^{\alpha N} Z_{N}(\alpha, \beta) \hspace{1cm} (3.127)$$ Where ##Q## is the grand partition function, ##Z_N## is the canonical partition function and: $$\beta = \frac{1}{kT} \hspace{1cm} \alpha = \frac{\mu}{kT} \hspace{1cm} (3.128)$$ In the case of an...
  19. Schwann

    I 'Conservative' p-values adjusted

    Hello everyone! Could anybody recommend some strategy of p-values adjustment, as the distribution of my p-values indicates the presence of a big number of false negatives? Usually p-values are adjusted in order to overcome Type 1 errors (e. g. FDR or FWER estimation), but what I need to do is...
  20. SamRoss

    I Seeking better explanation of some quantum stats formulae

    In "Introduction to Quantum Mechanics", Griffiths derives the following formulae for counting the number of configurations for N particles. Distinguishable particles... $$ N!\prod_{n=1}^\infty \frac {d^{N_n}_n} {N_n !} $$ Fermions... $$ \prod_{n=1}^\infty \frac {d_n!} {N_n!(d_n-N_n)!}$$...
  21. michaelwright

    B Can You Calculate the Odds of These Unlikely Events?

    Hi folks - I need some help with a tricky probability. Here's the situation: Let's say there are 4M internet users in Age Group A. (The total set) Of those 4M, there are 1,000 users who play a specific sport. Those 1,000 are spread evenly over 125 teams, so 8 players each. 1. What's the...
  22. H

    Other Programming in Statistics Careers

    [Mod note: post moved to its own thread] I have a question about statistic type of employment if you care to answer it. My question is in statistics type careers does programming matter more or does mathematical knowledge of statistics matter more? What I mean is that a statistic person...
  23. Avatrin

    Book that goes deep into the basics of statistics

    Summary:: Random processes, autocovariance, ergodicity, Gauss-Markov etc Hi I am a person who resolutely prefers depth over breadth, and currently I am trying to learn more about random signals and Kalman filtering. However, the books I have found so far will mention and superficially...
  24. The Parker Machine: it's 80% accurate.

    The Parker Machine: it's 80% accurate.

    Check out the full lecture on the Royal Institution YouTube channel.
  25. hagopbul

    Factors That May Influence Susceptibility to SARS-Cov-2: A Statistical Analysis

    Hello all: Hope all are fine and well , there is this question in relation to corona virus problem : Do anyone checked if the patients have any immunity related illnesses with the patients of SARS-Cov-2 Where I can find those statistics Best regards Stay safe
  26. Another

    I What statistics are used to test data like this?

    I have 100 data. if I want to use data from 10 to 100 or from 20 to 100, which statistic should I use to test whether I can use data from 1 to 100 or 20 to 100 without significance?
  27. Cesca Roma

    I Discriminant function analysis - stepwise or otherwise?

    I’m using discriminant function analysis to determine the potential accuracy of several biometric measurements being used in conjunction for binary classification purposes for my BSc Biomed research project. Overall I've only got 110 data points so it's a stretch but hey, that's anatomy! What...
  28. PainterGuy

    Stats on Students Understanding Theory of Relativity

    Hi, I'm not sure if it's a good idea to start a thread about the following problem but I didn't want to PM anyone. Some time ago I came across a thread which had stats related to the problems faced by students learning the theory of relativity. It showed like how many undergraduates really...
  29. S

    I What is the significance of this graphic (statistics)

    https://www.fmglobal.com/research-and-resources/tools-and-resources/resilienceindex/explore-the-data/? Below the world map, there is a horizontal graphic with dots corresponding to each country. The dots are broadly ranked from right to left according to a measure of "economic resilience", but...
  30. Kaushik

    Math: Question from KAPLAN (statistics)

    What exactly is the problem statement? what are they asking us to find?
  31. BlueKaiza

    Interpreting pie and bar charts

    Working 1. a (i) 1/4=×5% (ii)120/360×100=33.3% (b) newspaper=£9000 Leaf=£6500 Transport=£19000 55000-34500=£20500 Tv=16.7% 0.167×55000=£9185 ( answer) (c) Tv=16.7% News=25% Leaf=15.3% Other=9.72% Trans=33.3%(answer) Note: they were rounded to (3sf)
  32. MichPod

    I Why the statistics for a real gas are not quantum in nature?

    A gas of bosons or fermion particles follows a particular quantum statistics. Then why a molecular gas (say, H2) follows a classical distribution statistics? Is it not the case that the molecules should be indistinguishable one from another and be either bosons or fermions? What is exactly the...
  33. The Datasaurus Dozen

    The Datasaurus Dozen

    Same Stats, Different Graphs: Generating Datasets with Varied Appearance and Identical Statistics through Simulated Annealing
  34. AryaKimiaghalam

    Courses Taking statistics courses as a physics major

    Hi, I am currently a second year physics major. I have recently thought about taking statistics/probability courses as electives for the upcoming semester. However, I don't know what types of statistics/probability classes will help me in my physics education. I am not particularly interested in...
  35. JorgeM

    I Is this weighted mean and standard deviation correct?

    The expression I have found is this one. https://ibb.co/kqG24L3 I have been looking for information because I could not to realize what is the value that "alpha" has to have. If any of you do know what this alpha value is supposed to represent or if you have seen it before I would be really...
  36. Biochemgirl2002

    Clarification of the wording of a statistics problem

    i don't know what to do, but i am not asking help for the whole thing i am just wondering what it means by mean weight differs from 20g? from 1.5g-41.5g? or does it mean when the weight is not 20g
  37. parazit

    I Comparing theoretical calculations with experimental data

    Dear users, The situation I have encountered is a simple statistical comparison of the experimental data, which accepted as correct, with the results obtained via six theoretical models. In the experimental data, there exist y values corresponding to x values and also the measurement errors of...
  38. patric44

    Question in Bose-Einstein statistics

    iam not getting why in bose statistics the number of ways to arrange ni particles in gi degenerate states is = (gi+ni-1) ? and why do we divide by ni factorial , and gi factorial .
  39. Biochemgirl2002

    How do i find this statistics answer

    i believe that the solution is to do 1- (less than 2 did use google) so it would look like 1- ((20!/0!20!)0.76^0*0.24^20 + (20!/1!19!)0.76^1*0.24^19 + (20!/2!18!)0.76^2*0.24^18) = 0.99 but logically, this does not make sense to be .99. what am i doing wrong?
  40. Biochemgirl2002

    What Are the Tests for Independence in Probability Statistics?

    A) (0.5)-(0.3) =0.2 b) c) i have no clue how to determine from just a set of numbers if they are independant or mutually exclusive
  41. Biochemgirl2002

    How to use the word "Knowing" in statistics

    A vaccine has a 90% probability of preventing a certain disease. The probability of getting this disease if a person is not vaccinated is 50%. In a certain region, 25% of people get vaccinated against this disease. Find the probability that a randomly selected person from this region A. has the...
  42. T

    Other How Can I Explore Maxwell's Demon Through Far from Equilibrium Statistics?

    Hello! I would like your help to study Science graduate level books and articles, in the following subjects: 1. Far from equilibrium statistics. 2. Information theory and entropy. 3. Negentropy. 4. And Maxwell's demon. My main goal is to be able to understand and explore the Maxwell's demon...
  43. Biochemgirl2002

    How do i answer this permutation question?

    Question: A home security device with 10 buttons is disarmed when three different buttons are pushed in the proper sequence. (No button can be pushed twice.) If the correct code is forgotten, what is the probability of disarming this device? My attempt: 10!/(10-3)! =(...
  44. P-values Broke Scientific Statistics—Can We Fix Them?

    P-values Broke Scientific Statistics—Can We Fix Them?

  45. B

    I Finding CDF given boundary conditions (simple stats and calc)

    I'm not quite sure if my problem is considered a calculus problem or a statistics problem, but I believe it to be a statistics related problem. Below is a screenshot of what I'm dealing with. For a) I expressed f(t) in terms of parameters p and u, and I got: $$f(t)=\frac{-u \cdot a + u \cdot...
  46. Buzz Bloom

    I Questions about error range from Bayesian statistics

    About cosmology: https://www.physicsforums.com/threads/what-is-the-probability-that-the-universe-is-absolutely-flat.971984/#post-6180036 Planck paper: https://arxiv.org/pdf/1502.01589.pdf As in PCP13 we adopt a Bayesian framework for testing theoretical models. In the Planck paper, pages 38-40...
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