Statistics Definition and 998 Threads

Hello. I'm currently taking a lower level course in statistics. It is an okay course; however, it is not very rigorous and my professor is a "this is what you need to know" sort of teacher versus one who explains the theory and reasons behind the equations as well. The required textbook for...

Homework Statement Find the VaR for an investment of $500,000 at 1% given that the investment is expected to grow 10% every year with standard deviation of 35% and that the investment is held for two years. Homework Equations E(X + Y) = E(X) + E(Y) E(X*Y) = E(X) * E(Y) (for independent...

A few months ago I asked for recommendations for textbooks on generalized linear models. (Nevermind that I seem not to have actually asked anything.) I'm still in the same boat but am considering a different approach. I mention in that I felt approaching practical (mostly work) and theoretical...

Hi everyone. It's been years since I've done any stats, so I need a bit of help, please. I want to include it in a blog post I'm going to do (not here on PF), so I don't want to give away too many details :p I apologise for my terrible understanding of stats, please be patient! Anyway, over...

Hi, can you guys recommend a book for an undergrad that uses matrices properties to explain statistics? Thx!

Mod note: This post was moved from another forum section, so doesn't use the homework template. A study of the amount of time it takes a mechanic to rebuild the transmission for a 2005 Chevrolet Cavalier shows that the mean is 8.4 hours and the standard deviation is 1.8 hours. If 40 mechanics...

It seems to me that I've come up with a way to almost guarantee that one is a profitable trader. Obviously I'm assuming there is some flaw or it would be widely known as its not that complicated. Imagine thahe only knowledge you can ascertain about publicly-traded, liquid asset with constant...

Homework Statement The following represents the outcomes of a rolling a die 600 times. FACE Number 1 107 2 120 3 84 4 110 5 92 6 87 Given this data: A. What are the mean and median of appearances of...

Homework Statement I have two different experimental curves, and I would like to measure how closely a straight line fits each data, and which curve is more crooked. In statistics how can I measure this "linearity"? By the way this is about stepper motor step linearity (ideally it has to be a...

Homework Statement Given: Σ(xi - x̄)² = 500 Σ(yi - ybar)² = 800 (total sum of squares, SST)) Σ(ŷ - ybar)² = 400 (total sum of estimators, SSE) Σ(xi - x̄)²(yi) = 200 Σ(xi - x̄)²(εi) = 0 n = 1000 s² = 4 Find (or explain why you cannot find): β1 β0 variance of β R² Homework Equations [/B]...

Homework Statement Consider drawing one card from a deck with no jokers or other special cards. a) What is the number of microstates? (4/13/52/cant tell) b) What is the number of macrostates?(4/13/52/cant tell) c) What is the degeneracy of macrostate spade? (4/13/52/cant tell) d) What is the...

I am going through the tutorial athttp://scikit-learn.org/stable/tutorial/index.html Could anyone recommend a good book that could accompany this so I can gain a deeper understanding of the methods discussed.

Hi, I'm currently in grade 9 and I want to do the AP statistics and computer science exams in May. I go to semi-private computer classes on the weekends and the teacher there says he is going to prepare me for the AP computer science exam. Along with that I have a Barron's ap computer science...

Could I get hired with a B.S. in Computer Science degree that doesn't require any calculus based probability or statistics courses? It requires through Multivariable Calculus and Linear Algebra but no other mathematics courses besides Discrete Math. Here is the core of the program besides the...

So, the exercise is to find the expected value of following distribution: f(x) = 0,02x 0<x<10 answer in the book says 6,67 As far as I knowe, the expected value is calculated by the Integral of x * f(x) between 0 and 10, in this case! It looks like this won't give the result 6,67! what am...

Y and Z are independent N(0, 1) random variables. Let X = |Z|. Consider the random point (X, Y). (a) Derive the CDF FD(d) = P(D ≤ d) of the distance from the origin D = √(X2 + Y2). Sketch this CDF as a function of all real d. (b) The ratio T = Y/X has Student’s t-distribution with 1 degree...

Hello! (Wave) What is Parametric Statistics about? (Thinking) What knowledge is required? Is it difficult? (Worried) Would you suggest me to take Parametric Statistics or Stochastic Processes? :confused:

Homework Statement Prove that \sum[(x_{i} - \overline{x})(y_{i} - \overline{y})] = \sum[(x_{i} - \overline{x})y_{i}] Homework Equations None. The Attempt at a Solution I tried using the fact that the sum of the mean values is just the mean value, because the sum of a constant...

Homework Statement How many ways can 5 different letters be posted in 3 boxes, if any number of letters can be posted in all of the three post boxes? Homework Equations Order of the letters being put into the box doesn't matter, only which letter or letters ends up in which box. A box...

Greetings guys with highest IQ's on planet earth, Mine is not a physics question and my first post, but on a search I found other answers to this area of math so hoped someone might be able to help. I'm a 38 year old senior logistics manager without college education, looking to get an assoc...

Hey PF So I am writing a personal statement for a phd in statistics and i am not sure what all to include. each graduate school has very broad directions, and I'm not sure what to put. should i list a faculty member that interests me, or is that too much work? selecting one professor is...

Homework Statement Show that the given function is a cdf (cumulative distribution function) and find F_X^{-1}(y) (c) F_X(x) = \frac {e^{x}}4 , if x<0, and 1-(\frac {e^{-x}}4) , if x \geq 0 Homework Equations for a strictly increasing cdf, F_X^{-1}(y) = x \iff F_X(x) = y and for a...

hi guys, I wonder if I have fully understood the Fermi Dirac statistics properly, but I have a question on it regarding its application in the white dwarf research. I read the Fermi energy is applicable for T=0, now if the core of a white dwarf is too hot then how can we apply the Fermi Dirac...

Homework Statement Apologies if this is not meant to go into homework area; this is not a homework or coursework question, but more to convince myself that what I am reading is correct I have attached the diagram I am pondering over... How can I prove that if I want to differentiate...

Homework Statement Math and verbal SAT scores are each N(500, 10000) 1)If the math and verbal SAT scores were independently distributed, which is not the case, then what would be the distribution of the overall SAT scores? Find its mean and variance. Homework Equations The...

Homework Statement The Binomial Distribution - already developed by Jacob Bernoulli (in 1713), et alii, before Abraham de Moivre (1667-1754 CE), et alii, developed the Normal Distribution as an approximation for it (id est, the Binomial Distribution) - gives the discrete probability...

I'm studying by Statistical Mechanics (Huang, page 180) but can't understand many things there, can anyone provide a good bibliography to study this? I don't understand what's an occupation number of a given momentum: if it's the number of particles with that given momentum, why can it only be 0...

I've got some spare room in my fall schedule, so I'm looking to get an extra course in. My options are two introductory courses: Statistics and Algebra. Topics in statistics are: probability theory, random variables, marginal and condition distributions, discrete and continuous probability...

I recently got into UCSB to get me masters in statistics, but now I'm wondering if a master's degree is enough to land me a job( partly funded). UCSB offers two tracks in their statistics program which is the applied track and the other is much more theoretical. I've chosen the applied track...

First, sorry if this is in the wrong section. This could span many subjects. I was pondering on how reliable statistics in science are. My mother's best friend just had a baby naturally at 45 years old. I also know 3 other women who have had babies naturally after 40 (specifically 2 of them at...

1. A 2.5m aperture telescope obverses a star through an R filter. Assume that there is no noise associated with the detection system. The CCD has a full well depth of 20,000 counts and a gain correction factor of 1.00000. a. On average, the telescope detects 3 photons/sec from this star. What...

there are two type of charge carrier in semiconductor , one is electron which carry negative charge and other is hole which carry negative charge , electron meet with hole and they recombine , Q1 what is carrier transport Q2 what is carrier statistics in semiconductor

Hi awesome Physicsforum members, I’m looking for a good introdoctury book for learning Statistics (self-study) which succeeds in explaining the concepts very clearly . What I’m looking for in a statistics book My goal with the book is not to achieve some abstract mathematical skills, but...

Homework Statement The probabilities of blood types O, A, B and AB are 0.46, 0.39, 0.12, 0.03 respectively. If a clinic is seeking either type O or B from six random individuals, what is the probability that at least 2 people have the desired blood type? Homework Equations The...

Homework Statement Suppose you have a bucket containing a lot of balls with different colors. You randomly pick 50 balls, 9 of which are red (X = 9, where X ~ N(μ, σ²)). The probability of picking a red ball is 15%. From this you want to construct a 95% confidence interval for the standard...

Homework Statement http://www.math.ntnu.no/~haakont/grunnkurs/oppg/eksDes11e.pdf Please take the time to read problem 3 ("Oppgave 3) b, to understand what I am talking about. Everything's explained there. The specific part I am curious about: "Define a 90 % confidence interval for...

Homework Statement A container holds N molecules of nitrogen gas at T = 280K. Find the number of molecules with kinetic energies between .0300 eV and .0312 eV. dE = .0012 eV E = .0306 eV kT = 3.8668*10^-21 J or .02413 eVHomework Equations N(E) = (2N)(E^1/2)(e^(-E/kT)(π^-1/2)((kT)^-3/2)...

Homework Statement Suppose X1, X2, ..., Xn constitute a random sample from a population following N(μ,θ) where μ is known. (a)Find a sufficient statistic for θ. (b)Use the maximum likelihood estimator of θ to construct a confidence interval for θ with confidence level 1-α. Homework...

In the sample excel file(extract from .zip file) I have explained the calculation of contribution and R-Square. I need to solve 2 problems by adjusting the Multiplication factor or Coeff. I need to make sure actual contribution of current year and Previous year will be within expected Current...

I'm debating between majoring in Applied Math or Statistics ( which at the hands on school I'm going to attend, really should be called "applied statistics"). I am required to choose an emphasis for both majors, which i will choose computer science for either. Which major is going to be more...

Homework Statement 1. Assume each birth in a hospital on a given day is independent of one another, and each birth, P(boy)=0.48. What is the probability that the 8th baby born is the 5th girl. 2. Two random variables X and Y have joint distribution given by. What is their correlation. 3. Z...

I've taken a multi-variable calculus course already that covers infinite sequences and series, Taylor's theorem, quadratics surfaces, double and triple integration etc. I'm looking to get a Master's Degree in statistics two years from now, is there any point of me taking a class that involves...

I will be attending a graduate school (masters program) in fall not sure where I will be accepted. I was wondering in the meantime what could I do to become more employable. I've been reading and it says that knowing certain types of programming languages is necessary such as R and sql. I really...

Homework Statement The data contains 2500 integers, each is either a 0, 1 or 2: zeroes: 1240 ones: 1014 two's: 246 Does the data follow Poisson, geometric, binomial or negative-binomial distribution? Homework Equations The Attempt at a Solution The mean of the data is...

Homework Statement X is a random variable of binomial distribution of parameter n=10 and unknown parameter p. Hypotheses are given as follows: H_0 \;\; : \;\; p=0.6 H_1 \;\; : \;\; p \neq 0.6 Suppose rejection region for H_0 is \{X \leq 1\} \cup \{X \geq 9\} Question 1: What is...

Homework Statement Ok this might be a stupid question, but: https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-frc3/t31/q77/s720x720/10001118_10202561443653973_1625797585_o.jpg Why is this the case? I think for all of this to be right, then the assumption of ##Y=u(X) \Leftrightarrow...

Homework Statement If the probability density function (p.d.f.) of the random variable X is f(x| \theta ) =\begin{cases} \frac{1}{3\theta} & 0 < x \leq 3\theta \\0 & otherwise\end{cases} Where \theta > 0 is an unknown parameter, and X_1, X_2 … X_n is a sample from X where n > 2...

Homework Statement X_{1},\; X_{2},\;\;...,\;\; X_{n} are sampled from a normal random variable x of mean \mu =0 and variance 4 \sigma ^2 Question: What is the efficient estimator of \sigma ^2 Homework Equations Nothing Special.The Attempt at a Solution When \sigma is given, the...

Homework Statement These are taken from my class's lecture slides. I'm trying to understand the entire thought process and reasoning, so I'm just wondering what min and max mean in the g(x) function examples. Here is the first example: http://gyazo.com/7f9d707df0c8512bfa91a1f200dc3429.png...

Homework Statement What is the probability that among a collection of 20 assemblies we have exactly 2 loose-fits and 1 interference fits? P(loose-fit) = .1335 P(Interference fit) = .083 Homework Equations The Attempt at a Solution I am thinking that I just add the two...