Statistics Definition and 998 Threads

Statistics. The bane of my existence... and then a bit of statistics "revision" rears its (in my opinion) ugly head in my quantum physics course and I have absolutely no idea what to do. Homework Statement 1. Suppose you measure the height of all students at the University. You use a ruler...

http://prola.aps.org/abstract/PR/v58/i8/p716_1 I'm trying to read this, and it's not going very well! :frown: On the second page: What two numbers is Pauli talking about? Isn't a spinor of a particle usually characterized by a one number?

Hello, I'm studying for a final exam and I'm having trouble with this particular question. I attached the data required to solve the problem. I am required to fill in the missing information in the data. I've defined the acronyms below: SSE = Sum of Square Errors MSE = Mean Square of...

Hi there, I am thinking if statistics can tell us if a slot machine is fair or not? We know that there are so many outcomes of a slot machine and seems it is not practical to sample all possible outcomes to check if it is fair or not. So how does statistics work in this issue?

I mentioned in a thread on here almost a year ago now that I was considering making a change into math, after entertaining several other options and figuring out that I really enjoy math, and especially probabilty, I have decided to to move toward getting either another bachelor or a masters in...

How are IGE antibodies related to an increase of allergies in the world?

The average amount of time people spend on facebook each day is 64 minutes, with a standard deviation of 4.5 minutes. Are you more likely to select a random person that spends less than 62 minutes per day, or a group of 35 people that spend on average less than 62 minutes per day on facebook...

Hi all, Just looking for some opinions on how to approach reporting the variability in some data I have acquired. I know Rutherford is quoted as saying “if your experiment needs statistics, you ought to have done a better experiment”, but unfortunately in biophysics we’re always at the mercy...

Hi all, I've search for my question and found no answer. I think it should be pretty simple... Fermi energy corresponds to the last occupied energy, as I understand it. So, energy levels in the Fermi gas are all filled with two electron of opposite spins, up to the Fermi energy. Saying it...

Homework Statement Three cards are dealt from a well-shuffled deck. (a) Find the chance that all of the cards are diamonds. (b) Find the chance that none of the cards are diamonds. (b) Find the chance that the cards are not all diamonds. Homework Equations Not sure ... The...

Hi, I am curious about how to describe the stability of a graph using some form of bona fide statistical analysis. I unfortunately have very little statistical background. The data come from a Computer Science research project I am working on. We are attempting to use simulated...

Hey I am transfering to the University of Florida next semester. Which one of these classes is easier? Business Statistics or Calc 1 w/ analytical geometry? I want to go higher up in Math and I was thinking calc 1 w/ analytical might help me before I take Business Statistics? Right now I am...

Which one do think is better for physical science?...one which help the most!

Hi. I am going to have my Multivariate Statistics exam in two weeks. I am going by a book that isn't available in the English literature. But I don't like it, because it has several omissions. Can you recommend me any good books in English? I can borrow many (for free) at my institution's...

Hi all, I was wondering if there was a way to see 1) average Physics GRE score 2) average GPA 3) average # of publications 4) etc.? of admitted grad students for a given PhD program. It seems to be of no use contacting the individual departments to see if my application is strong enough to...

Hello! I was given the following exercise in Statistical Data Analysis: The method of least squares is often used for straight lines fits y(x)=mx + c to data (x_i,y_i) Assume all y values have the same (uncorrelated) statistical uncertainty \sigma and that they share a common (fully...

Homework Statement The Attempt at a Solution The textbook says the answer is 0. I think they get that by saying that 5% of 240 is 12. So the plane is overbooked by 12. So there are 252 people booked on the plane. Then the binomial expectation is (252*0.95)=239.4. Which means they payout...

Homework Statement I need help solving this problem: Let A, B, C, D, and E are 6 units of a population. The measurements associated with A, B, C. D, E units are 76, 77, 78, 81, and 82, respectively. -Find the population mean and its standard deviation -List all possible samples of size 3...

1. Some programs put time to completion at 4-5 years. Is it thus easier to graduate compared to other disciplines? 2. Is it time inefficient to do an MS stats one place and phd at another? Does this involve more courses than a direct phd after BS? 3. Is it more common to apply w/ MS or BS...

Homework Statement The entering class in an engineering college has 34% who intend to major in mechanical engineering, 33% who indicate an interest in taking advanced math as part of their major field of study, and 28% who intend to major in electrical engineering, while 23% have other...

Hello, Suppose we have the following set of independent and identically distributed exponential random variables: \gamma_1,\,\gamma_2,\ldots ,\,\gamma_N. If we arrange them in ascending order we get the following order statistics: \gamma^{(1)}\leq\gamma^{(2)}\leq\cdots\leq\gamma^{(N)}. I...

Homework Statement I have a table of paired measurements: IQ and brainsize of a person. Question: is there a significant connection between brainsize and IQ?Homework Equations / The Attempt at a SolutionThe only test in my course notes that checks indepedence of continuous variables is a...

Homework Statement At the 5% level, will the two means be equal ? Homework Equations The Attempt at a Solution I tested the variances and found out that it's very likely that the variances are equal, so this is an assumption we make when we do the second test. Now, I'm trying...

Homework Statement I got a stats problem which I don't know how to approach. It concerns a method of predicting election outcomes based solely on the length of incumbency of an existing Government. For Australian National or State governments elected the lengths of holding office are...

Ok so my question is as follows: Can Maxwell Boltzmann statistics be used to describe electrons in a metal at room temperature? I know that the Fermi Temperature in metals is about 10^4 K or something rather high, so does that mean that the metal / electron gas would need to be at a...

Hello everyone, I'm currently deciding where I should study next year, and I would appreciate any advice you could give. I am a Canadian citizen, and I just finished my bachelors with a physics/statistics double major. My long term goal is to research machine learning, either in a faculty...

I'm a senior undergrad student and I am going to give a 50 minute lecture on Degenerate Fermi Gases to the Thermodynamics and Statistical Mechanics class. I was wondering if anybody could help me out with coming up with some interesting stories, factoids, thought experiments, history lessons...

The Constraint Based Statistics --- Beyond the Entropy Based Statistical Mechanics The Constraint Based Statistics --- Beyond Tsallis Entropy and Boltzmann Entropy Based Statistical Mechanics This post is a summary about a brand new work in the field of Nonextensive Statistical Mechanics...

I'm a senior undergrad student and I am going to give a 50 minute lecture on Degenerate Fermi Gases to the Thermodynamics and Statistical Mechanics class. I was wondering if anybody could help me out with coming up with some interesting stories, factoids, thought experiments, history lessons...

Homework Statement Consider the distributions N(mu1, 400) and N(mu2, 225). Let theta = mu1-mu2 and x and y be the observed means of two independent random samples, each of size n, from these two disbtibutions. We reject H(0) : theta = 0 and accept H(a): theta >0 if and only if x-y >=C. If...

Homework Statement A u-shaped tube open to air at both ends contains some mercury. A quantity of water is carefully poured into the left arm of the tube until the vertical height of water is 15 cm.Homework Equations (a)What is the gauge pressure at the water-mercury interface?[ans 1.47*10^3Pa]...

Learn "advanced basics" of statistics? I'm a physicist and would like to prepare for a job interview where the job is to do statistical analysis and optimization of models for medical data or so. The firm does consulting for pharmaceutical companies. Anyway, I know the very basics of...

Right, the question is how much Stats do I need? I am aiming for a double major in Math and Physics I know that at some point I will have to take First-year stats (AP Statistics?), but what is beyond that? How many of those permutations/combinatorial courses will I need? By the way, I am a...

Suppose that the mean score of a class of 30 students was 78. The 19 male students in the class had a mean score of 68. What was the mean score for the 11 female students? advice? thanks.

Hello friends! Given an estimator of the population mean: \bar{Y}=\frac{\sum^{N}_{i=1}Y_{i}}{N} The expected value of \bar{Y} is : E(\bar{Y}) = \frac{1}{N}E(Y_{1})+\frac{1}{N}E(Y_{2})+\cdots+\frac{1}{N}E(Y_{N})=\mu where \mu is the population mean. Therefore: E(\bar{Y}) =...

Homework Statement A plant manufactures 500 components a day with the diameter being random variable: N(8.02, 0.1^2)mm What is the probability of two randomly picked components differing by more than 0.3mm?2. Solution I know that the solution is 0.966The Attempt at a Solution I thought that I...

Hello, a very interesting forum you have here:) So, to business The topic says it all - I'm looking for a good textbook for undergraduate on probabilities and mathematical statistics. Could you recommend something? I thought about: First Course in Probability by Sheldon Ross, but I have read a...

Homework Statement X is a discrete random variable that has a Poisson Distribution with parameter L. Hence, the discrete mass function is f(x) = L^{x} e^{-L} / x!. Where L is a real constant, e is the exponential symbol and x! is x factorial. Without using generating functions, what is...

Suppose that I can sample from some unknown continuous distribution. I know that the draws are iid, but the distribution itself is unknown. However, I know that the true distribution is one of two, either f(x|H) and f(x|L) with common support. I form the likelihood ratio...

Today in class, by the existence of an operator that exchanges the states of two indistinguishable particles, we attempted to derive the existence of fermions and bosons & how this relates to the symmetries of multiparticle wave functions. The argument given in my textbook is: define an...

I have a degree in Engineering. Now I am back to school, for a 2 year Master's degree in Statistics. The second semester just started. And there will be a 3rd. Is there a chance that I will need complex numbers? My background in Complex Analysis is very limited. Should I study any Complex...

Homework Statement Suppose that n=5 observations are taken from the uniform pdf, fY=1/\Theta 0<y<\Theta where \Theta is unknown. Two unbiased estimators for \Theta are \Theta1= (6/5)*Ymax \Theta2= (6)*Ymin which estimator would be better to use? hint: What must be true of Var(Ymax) and...

Homework Statement There is some question, I solved it but am not sure I got the right answer. Let Y1, Y2... Yn be a random sample of size n from the pdf fY(y;\Theta= \frac{1}{\Theta}*e-y/\Theta , y>0 Let \Theta_hat=n*Ymin is tex]\Theta[/tex]_hat for \Theta ? Homework Equations...

I'm a sophomore in math.I intend to learn mathematical and physics something like differential geometry,topology and QFT in my next years and do some research in some relative topics.I know I need to learn many courses and I feel I don't have enough time.This semester we open a course called...

Homework Statement A random sample of size 2, Y1 and Y2, is drawn from the pdf fY(y;\vartheta)=2y*\vartheta2, 0<y< 1/ \vartheta What must c equal if the statistic c(Y1+2Y2) is to be an unbiased estimator for 1 / \vartheta Homework Equations The Attempt at a Solution I tried...

Nonlinear ODE's versus "Statistics". Hi all, My university offers a course on Probability followed by a more theoretical course on Statistics (not sure how standardized the names are). They also offer a nonlinear ODE course. From a physics major's point of view, which subject is harder...

Homework Statement Two cards are drawn from a standard deck with replacement. A=first card is an ace. B=second card is an ace. Show that A and B are independent Homework Equations P(A and B)=P(A given B)/P(B) P(A given B)=P(A) The Attempt at a Solution P(A)=4/52 P(B) =4/52 P(A...

This is for my Statistics and Stochastic Processes class, we are learning about random walk [b]1. Let p<q where p is success (+1) and q is failure (-1). Let T=last time we hit 0 (T\geq0) Find P(T=t) Then using the answer from the above question, make up a formula for \sum(2n choose...

URGENT help needed with statistics, probability Homework Statement 1) A plane functions iff at least 2 of its 3 engines function. P(each engine functions)=p, the engines operate independently of each other. Find the probability that the plane functions. The Attempt at a Solution...

1) Distribution is a uniform distribution on the interval (Ө, Ө+1) Show that Ө1 is a consistent estimator of Ө. Ө1=Ῡ -.5 Show that Ө2 is a consistent estimator of Ө. Ө2=Yn – (n/(n+1)). 2) I think the distribution for this one is a uniform distribution on the interval (0, Ө) but...