Statistics Definition and 998 Threads

sometimes in statistics there is a prime ( ' ) after the variable for moment ( u sub r ) what does that mean?

Suppose that there are m independent and identically distributed variables Y1, Y2, ... Ym. Yi - are random variables. Let Y denote the maxof Y1, Y2, ... Ym. What's the distribution of Y when m is very big? Thank you for any help, in advance.

I have a question about an entry on the following Wikipedia page - tf-idf ( term frequency–inverse document frequency). In the Matematical Details section where they are describing the inverse document frequency as follows: idf(t, D) = log \frac{|D|}{|{d \in D : t \in d}|} This is my...

Let X1, X2, …, X10 be a random sample of size ten from the Normal(3, σ^2) distribution. (a) Use the likelihood ratio test to derive a 5%-level critical region for testing H0 : σ^2 = 1 versus H1 : σ^2 ≠ 1. (b)Suppose the following ten values from the Normal(3, σ^2) distribution are observed...

I need answer of thees question The amount of money saving accounts at BOC bank at the end of april 2010 had mean of R.s 3460 with a standard diviation R.s 550 1.if it is assumed that these bank balances are normally distributed find the probability that a single randomly chosen account had...

When conducting a survey it is poor choice to only solicit the survey to people who feel like taking it. This is a bad idea because a person who goes out of their way to do a survey may be different than the rest of the population in some respect thus their answer is biased. I know this is...

Hey all, back with another question. I have the opportunity in the fall to choose 1 (maybe 2 if I'm lucky) of the following classes: Numerical analysis (undergrad numerical linear algebra, using matlab), Functional Analysis (as a directed study course with a prof), and the other is doing a...

I was recently made a manager of my high school's basketball team. I have been asked to look into creating a program that will allow statistics to be used in sports. I do not know much about sporting statistics, so I was wondering if anyone could help me figure out what direction to look in. Thanks!

I'm a little confused on how you would do something like this: I have a cumulative probability distribution H(x): 0 0.31042 1 0.67825 2 0.89149 3 0.97196 4 0.9942 5 0.999 6 0.99985 7 0.99997 8 1 and I need to find the 90th percentile of demand.. I understand...

Hi, I have a general concept question. I am working with finding complete sufficient statistics of distributions. Sometimes I need to condition some function of a parameter on a sufficient statistic, using basically Rao-Blackwell, but my trouble is in finding the conditional distributions...

Homework Statement The following data is hypothesized to possesses a normal distribution, is that hypothesis sustained by a Chi-square test at .05 significance: <66...4 67-68...24 68-70...35 70-72...15 72-74...8 >74...4 The Attempt at a Solution 1. I know that I should...

Homework Statement Uploaded Homework Equations Uploaded The Attempt at a Solution Is my work correct?

Is it possible to combine statistics from two distributions for the same parameter. For example I have one distribution for X from population A and a second distribution for X from population B. I want to assume all data is from the same population. I have calculated UTLs(Upper tolerance...

Homework Statement Uploaded Homework Equations P(y)=(n c y)p^y(q^(n-y)) this is also uploaded The Attempt at a Solution My attempt at the first two parts is uploaded I am really confused on how to do game 6 and 7. Also I am a bit confused on how what I did worked in P(y=5), as the...

how are cdf and pdf related in statistics? please help i have a test tomorrow

My statistics professor wanted me to remember an infinite series sum, but i can't remember what it was i think it was either ( E(1/n^2) 1 to infinite ) or ( E(1/(L+n^2)) 0 to infinite ) or ( E(a^n) 0 to infinite where n is between 0 and 1) i think it was the 2nd one, does anyone know how to...

What are the formulas for entropy and internal energy in Fermi-Dirac statistics, and how do I derive them?

1. If a pair of coils were placed around a homing pigeon and a magnetic field was applied that reverses the earth’s field, it is thought that the bird would be disoriented. Under these circumstances it is just as likely to fly in one direction as in any other. Let θ denote the direction in...

This is a really basic point that I am getting held up on. In probability theory, we use PDFs and PMFs to describe random variables. (The term "random variable" carries a certain connotation of "unpredictable variations when repeated.") For example, the number of heads we will see in 50...

Homework Statement You use a standard gram weight of known weight (x) to check the accuracy of a balance. For one balance, this standard is weighed 3 times yielding the following values; a, b, and c. Calculate the 95% confidence limit for the mean Homework Equations general statistics...

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...

Homework Statement If the number of complaints a dry cleaning establishment receives per day is random variable having the Poisson distribution with λ = 3.3, what are the probabilities that it will receive: (a) Five complaints altogether on any two given days. (b) at least 12 complaints...

Hi, I am trying to show that if the E[W|X]=0 then the Cov (W,X)=0. Using the def of variance, and given that E[W] is zero, I get that Cov is equal to: E[WX]-E[W * E(X)] using conditional expectation: E [E(WX|X)] -E[x]E[W]= E[X E[W|X]]-E[X]E[E(W|X)]=0 I am not sure if...

Homework Statement The number 15 is added to each of the biggest 150 numbers in a distribution of 301 numbers in other words n=301 A. How does this addition affect the median of the distribution B. how does this addition affect the mode of the distribution C. How does this addition affect...

1. A Poisson random variable is such that it assumes the values 0 and 1 with equal probability. Find the value of the Poisson parameter, ρ ,for this variable. 2. Poisson equation: f(x) = e-λs(λs)/x! 3. I assumed the probability would be 0.5 because it can be either 0 or 1. 0.5 = e-λs(λs)/x! But...

I'm contemplating the possibility of teaching either a regular probability and statistics course or maybe even the AP Stats course at my high school next year. However, I only took the first semester in statistics at the junior level in college (used multivariable calculus); that means I got...

1. It is known that the probability of being able to log on to a computer from a remote terminal at any given time is .7. Let X denote the number of attempts that must be made to gain access to the computer. a) Find the first four terms of the density table. b) Find a closed form expression...

The Basic Practice of Statistics by David Moore Author: David Moore Title: The Basic Practice of Statistics Amazon Link: https://www.amazon.com/dp/1429230932/?tag=pfamazon01-20 Prerequisities: Calculus 1,2,3, Linear Algebra Table of Contents: To the Instructor: About This Book To the...

Homework Statement Problem is in the attachment, sorry, I can't figure out how to do tex in this message board system. Homework Equations The Attempt at a Solution In the attachment.

First of all I apologize for my lack of English skills in the world of chemistry. I've just started taking a very basic course in Chemistry and one week in an experiment got me wondering. Na_{2}SO_{4} (aq) + BaCL_{2} (aq) \rightarrow BaSO_{4} (s) + 2NaCl (aq). Now my teacher kept saying...

1. Assume that there is a 50% chance of hard drive damage if a power line to which a computer is connected is hit during an electrical storm. There is a 5% chance that an electrical storm will occur on any given summer day in a given area. If there is a 0.1% chance that the line will be hit...

Hello! I have a small question, and I am not sure if I am missing something: Today I glanced at the wikipedia page for Pions, and saw this: Statistics: Bosonic Can anyone explain to me why a quark paired with a anti-quark obey Bose-Einstein Statistics? If quarks obey Fermi-Dirac statistics...

Hello, I've got some data on an epidemic in various locations - the total number of agents and number killed by the infection after 1 year. -This gives gives me a distribution of percentages of the populations that have been killed by the infection. (but all the percentage values are relatively...

This is difficult for me to describe. If anyone can get the gist of what I am talking about and can point me to the correct keyword, would be really helpful. I'll explain this through an example: I have many perfumes. I get surveys from people to see which perfumes they like more. The way...

This is NOT homework. This is a personal project I am working on. First and foremost, THANK YOU in advance for helping me with my statistics project that I have been unable to solve on my own or through the help of my statistics book and google. I am working on an excel spreadsheet for use...

What are some good texts for self-studying probability & statistics?

What does the term 'absolutely fair' in statistics & probability mean? Does it mean that the probability for each variable* is 0. And that the expected value is 0. I did a search on Google and the only thing I came up with was this: http://mathworld.wolfram.com/AbsolutelyFair.html

Any comments would be appreciated. Patent/Copyright Pending. :approve: Thanks ********************************SOP Follows************************** Statistics’ use in predicting and modeling are the most attractive to me. The ability to model phenomenon and...

Homework Statement Let X= \begin{bmatrix} X_1 \\X_2 \end{bmatrix} be bivariate normal N(\begin{pmatrix} \theta \\ \theta \end{pmatrix}, \begin{pmatrix} 1 & u \\ u & \sigma^2 \end{pmatrix}). Let T=aX_1 + (1-a)X_2. a) Write u in terms of \rho = the correlation coefficient, and \sigma b)...

Homework Statement Roll a pair of six-sided dice. If the sum is 7 or 11, you win. If the sum is 2,3, or 12, you lose. If the sum is any other number, you roll again. In fact, you continue throwing the dice until you either roll that number again (win!) or roll a 7 (lose!). Suppose you...

Let X be \Gamma(3.5,2). Find E(X^3). We can't write E(X^3)=E(X)E(X)E(X), right? (since they are not independent)... So I just tried to compute: E(X^3) = int_0^{/infty} \frac{x^3}{\Gamma(3.5)2^{3.5}} x^{3.5-1} e^{-x/\beta} dx But I'm having a problem, since \Gamma(3.5) = (3.5)! and I don't...

Let \bar{X} be the mean of a random sample of size n from a distribution that is N(\mu,9). Find n such that P(\bar{X}-1 < \mu < \bar{X}+1)=.90, approximately. My answer: -Z^* < \frac{\bar{X}-\mu}{9/\sqrt(n)} < Z^* where -Z^* and Z^* are the critical values. So... For the confidence...

Hope this is the right forum for my question. I'm into statistics and quite often see assumptions involving set theory. I know some set theory but am having trouble understanding it for any application. I would like to narrow this gap, maybe because this type of mathematics seems most...

In this link: http://www.math.harvard.edu/~phorn/362/362assn3-solns.pdf I do not understand how they got the power function for number 5...can anybody explain it to me please? Thanks in advance

Homework Statement OK I am dealing with a Queue type problem that is M/M/2. I have already solved most of the problem but I can not figure out how to solve for ∏0, Lq, L, & W. The information I am given is: λ=11.98, μ=7 and s=2. Homework Equations The Attempt at a Solution I am...

this isn't really homework, but I was just wondering if someone could offer an intuitive reason as to why when random variables are transformed, we use absolute values of derivative of those functions, as opposed to the functions themselves?

Homework Statement Given two events, A and B, state why each of the following is not possible. Use formulas or equations to illustrate your answer. d. P(B) = 0.24 and P(B|A) = 0.32 Homework Equations P(A ∩ B) = P(A) * P(B|A) P(B|A)= (P(A ∩ B))/P(A) P(A|B)= (P(A ∩ B))/P(B) The...

Hey, how can I run a analyse with SPSS statistics software for this data? (I am not a stats guy at all, and not sure about using SPSS) Group 1 is "Gym A" Group 2 is "Gym B" And the values are just the weight loss numbers. All we are trying to do is compare Gym A (group 1) to Gym B...

I am reading Henk Tijms' "Understanding probability" and have become a bit confused. A man deposits $100,000 in a pension fund for 20 years with an average growth of 14%. Assuming a fixed rate of growth of 14%, the book tells me that the equation below, solved for x, will give me the amount...

I'm currently taking a intro to statistics class. It's a quarter class so it just started a week ago. I got a lot going on this semester so after taking the class I feel I'll only have a computational aspect for statistics. I won't know much about the theory because I know I won't have much time...