Distributed Definition and 210 Threads

Dear Good people, I needed a help, what will be the distribution of sum of n F distributed random variables? what will be the distribution of sum of n non-central F distributed random variables? Great if u can suggest some references too! Thanks in advance!

Question: X is normally distributed and the mean of X is 12 and standard deviation is 4 Find i)P(0<=X<=12) Solution P(X=12) = Z(12-12/4) =0 Stuck here! what to do next

Hello, I am attempting a problem in an older statics textbook an image of which is attached. No matter what I try, I get a solution of between 0.52 and 0.53 metres and was hoping someone could verify if the textbook answer of 0.48m is right or wrong. Thanks Heaps, Scott.

Question: What is the probability that a random variable X with domain all real numbers will take a value in the closed interval [a,b]? It seems to me that in order to answer this question you have to know how the real numbers are distributed. Given the appropriate distribution function, you...

Question: Let X be uniformly distributed on (0,1). Show that Y=- \lambda-1 1n(1-X) has an exponential distribution with parameter \lambda>0

I am given that the lowest value on a graph is 0 and that it's SD is 20, but I need to find the mean? How would I do that? I would think to use the Z-test formula but I keep getting 0 which is wrong for sure since 0 is the lowest value of the graph Thanks

1. Suppose that two electronic components in the guidance system for a missile operate independently and that each has a length of life governed by the exponential distribution with mean 1 (with measurements in hundreds of hours). (a) Find the probability density function for the average length...

This is a question from the GRE General Test, which I am not able to understand its solution. Maybe someone can help ^^ Question: The variable X is normally distributed. If the values of Xat the 45th,15th and kth percentile are 550, 350 and 450 respectively. (A) K (B) 30 Answer...

Hi , I got this question in my midterm today but up till now I don't know how to solve it , The Question is as follow : If X and Y are two exponential Rv with different lambda . and there's a new Rvs Z and U are defined such that : Z= 0 : X<Y and 1 ...

I've been struggling with this problem for more than 4 days now: Let A, B and C be exponential distributed random variables with parameters lambda_A, lambda_B and lambda_C, respectively. Calculate E [ B | A < B < C ] in terms of the lambda's. I always seem get an integral which is...

I'm looking for a good distributed circuits book.. Does anyone have recommendation ?

1 Calculate the expected value of variable x (or E(x)) (number of trials * probability of success) 2 Calculate the variance (expected value * probability of a failure) Take everything to the right of the decimal in the variance off. Then the range of future values is E(x) plus/minus the variance.

Homework Statement Variables X and Y are uniformly distributed on [-1,1] Z = X^2 + Y^2 where X^2+Y^2 <= 1 Show that Z is uniformly distributed on [0,1] The Attempt at a Solution If we set X=Rcos(theta) and Y=Rsin(theta), the joint pdf is R/pi where 0<=R<=1 and 0<=theta<=2pi...

hello if we have set of stochastic variables representing the random time it takes to do something: X,Y,Z,W and C where C is the sum of X Y Z W, thus the time it takes to do these things in sequence. If: X: N(30,5) Y: N(30,3) Z: N(20,2) W: N(40,7) makes C adding these together right, mean plus...

Hi, I understand how to get the electric field between two spheres of uniform charge, \vec{E} = \frac{\rho \vec{d}}{3 \epsilon_0} which is simplified because at a point \vec{r}, the vectors from each charge center combine to give the distance, \vec{d}, between centers (since \rho's can...

forgive for my ignorance, but i have a practical problem that i don't know how to approach: X\sim\mathcal{N}(\mu,\sigma^2) where \mu\sim\mathcal{N}(\mu_{\mu},\sigma_{\mu}^2) and \sigma\sim\mathcal{N}(\mu_{\sigma},\sigma_{\sigma}^2) what is the resulting distribution of X, in terms of...

Homework Statement A horizontal beam 8m long, resting on two supports 1.5m from each end (supports are 5m apart), carries a uniformly distributed load of 25kN/m between the supports, with concentrated loads of 20kN at the left end of the beam, 30kN at the right end, and 40kN in the centre...

Are galaxies fairly evenly distributed regardless of which direction we look out from? Also are the oldest stars and galaxies that we can view also relatively evenly distributed in all directions? I am asking because assuming that we are not in the center of the universe, I would imagine...

Homework Statement To find the reaction at A and B. (See image below) Homework Equations Moments and Area The Attempt at a Solution Area of load: (0.3)(6) = 1.8kN Moments about A: -(6)(0.15) + RB(0.6) = 0 --> RB = 1.5kN 4. The error and question I get the reaction force at...

I am a little fuzzy on the meaning of Independent Identically distributed random variables. I understand the independent part but still not 100% on the identically distributed part. I understand that identically distributed means they have the same pdf and cdf but does this mean that they have...

I once ran into a nobel-winning astronomer at a conference and suggested to him putting small internet-controlled telescopes for free (and fully supported) on a the roof of any household that wanted one. The telescopes would be controlled by "The Project" from a central server, and the "owner"...

The life of a light bulb manufactured by a company is found to be normally distributed. if the bulbs last 400 days with a standard deviation of 75 days, what is the probability that a randomly chosen light bulb lasts? a) at least 450 days? b) less than 150 days? etc. Throughout the...

Hi! What the difference between Clustered systems and Distributed systems? Can any help in a few lines? Thanks.

Homework Statement How many rice grains are needed for an electric charge of a certain strength (I don't remember the value now but is it really relevant?) to be equally distributed amongst them? Homework Equations I hope you can answer that :) The Attempt at a Solution I can...

Hello, I am having difficulty approaching this problem: Assume that K, Z_1, Z_2, ... are independent. Let K be geometrically distributed with parameter success = p, failure = q. P(K = k) = q^(k-1) * p , k >= 1 Let Z_1, Z_2, ... be iid exponentially distributed random variables with...

1. A solid conducting sphere is given a positive charge Q. Why is the charge uniformly distributed on the surface of the sphere only? Homework Equations 3. I know there are electron clous where electrons hang out, but what happen when the sphere is given a postive charge? I don't...

I am looking for a Hoeffding-type result that bounds the tail of a sum of independent, but not identically distributed random variables. Let X_1,..,X_n be independent exponential random variables with rates k_1,...,k_n. (Note: X_i's are unbounded unlike the case considered by Hoeffding) Let S=...

Homework Statement Suppose U follows a uniform distribution on the interval (0, 2pi). Find the density of sin(U) Homework Equations The Attempt at a Solution Well if U ~ (0, 2pi), then sin(U) should follow a distribution on [-1, 1]. I know one way to do tackle such problems is to...

Homework Statement Let (S, \Sigma, P) be a probability space. Let X and Y be two random variables on S that satisfy P \circ X^{-1} = P \circ Y^{-1} (i.e. they are identically distributed) and such that E(X), E(Y), var(X) and var(Y) exist and are finite. Prove that E(X) = E(Y) and var(X) =...

Homework Statement A beams is 3.0m long, it rests on two wide supports. The support A is 0.5m wide. Support B is unknown. Point A is taken to be the end of the beam on your left. Support A has a loading intensity of 75 N/m. The load on the beam acts with a force of 300N, 2.0m from...

Homework Statement A positive charge is placed in the center of a cube. Are the intersections of the field lines with a side of the box uniformly distributed across that side. Explain. === I have missed some lectures due to getting the swine flu (ugh) and the material is not exactly...

Let \left(a_n\right) be the sequence \frac{1}{2},\, \frac{1}{3},\, \frac{2}{3},\, \frac{1}{4},\, \frac{2}{4},\, \frac{3}{4},\, \frac{1}{5},\, \frac{2}{5},\, \frac{3}{5},\, \frac{4}{5},\, \frac{1}{6},\, \frac{2}{6},\,\mbox{...} Suppose that 0\leq a<b \leq 1. Let N(n;a,b) be the number of...

Hello, I want to simulate a plane thin rectangular board attached to one spring below at each end. (So there are 2 springs in total.) The springs span the entire edges. The spring-board-attachment is a rotatable axis. I can't find out how the force acts on the springs. I don't know whether...

Homework Statement A standard light bulb is claimed to have a lifelength of 8000 hours with standard deviation of 800 hours. A newly designed light bulb is claimed to have a life length of 9200 hours with a standard deviation of 600 hours Homework Equations If 36 standard and 36 newly...

Does anyone else here do distributed computing? I have my PCs running World Community Grid and work on the Clean Energy Project. Does anyone else participate?

Hello, When writting a gamma distributed RV we need to know the shape and scale parameters. How to find the value of these parameters? Thanks in advance

Homework Statement an exam is normally distributed with a mean of 75 and a variance of 64. students with a mark of 90 or above receive an A+ a) what percentage of students receive an A+? b) if 12 students write the exam what is the probability 3 get A+? Homework Equations z-score-...

An annulus (disk with a concentric hole) has inner and outer radii of R1 and R2 respectively, and uniform surface charge density of \sigma. the annulus lies in the xz plane with the y-axis centered in the hole. a.) using the most basic expression of point charge electric field as a starting...

Hi, Can anyone derive the sum of exponentially distributed random variables? I have the derivation, but I'm confused about a number of steps in the derivation. Here they are: Random variable x has the PDF, f(s) = \left\{ \begin{array}{c l} e^{-s} & if s \ge 0 \\ 0 &...

Homework Statement I have the classic slit-diffraction experiment, where light is incident on two narrow slits on a screen and is diffracted to create a pattern of maxima and minima on the far surface. It is usually assumed that the light incident on the slits is uniform. In practice, the...

Hello, I am an amateur developing the math to describe the motion of a robot of sorts. At this stage I'd like to use http://en.wikipedia.org/wiki/Bézier_curve" as user input to describe the motion path/s that it will make over time... (imagine it sitting flat on the cartesian 'floor')...

Homework Statement A simple beam is under a distributed load q=c*sine(n*pi*x/L)? if there are two pivots at the end points supporting it, what will be the reactionary force on each one of them? Here, L is the length of the beam and x=0 is the leftmost point. 0\leqx\leqL The figure...

This was mentioned casually in my controls book concerning differential equations. Using simple english please describe to me what the two are. Please avoid any and all equations unless absolutely necessary. Thanks!

Why is matter not uniformly distributed across space time?? I was wondering why there is varying densness across space time and not uniform distribution of matter. and slighty linked to this, what is it that holds matter together, but also keeps it apart if that makes sense?? ie atoms bond...

Just curious to know if you guys here support Distributed computing? like boinc. do you? and what particular project do you support.

For two independent and identically distributed random variables having the exponential distribution, do they have the same lambda value, or are the lambda values different?

Hi I have a question regarding i.i.d. random variables. Suppose X_1,X_2,\ldots is sequence of independent and identically distributed random variables with probability density function f_{X}(x), mean = \mu and variance = \sigma^2 < \infty. Define Y_{n} = \frac{1}{n}\sum_{i=1}^{n}X_{i}...

Homework Statement rod -a-------|---------a on x-axis, for x>-a has -Q charge, for X<a has +Q charge, find the electric field at point (x,0) x is positive Homework Equations lambda = Q/a linear charge density dQ = (lambda)(ds) E=KQ/r^2 The Attempt at a Solution i make...

I've attached a picture of the problem - I'm NOT looking for a solution, just an explanation. You can see the dimensions x,y, and z. That box is a detail of the connection at the rod interface. There is a distributed load acting across the lower beam of w lb/ft. Given the allowable...

Homework Statement A ring-shaped conductor with radius a = 2.20 cm has a total positive charge Q = 0.123 nC uniformly distributed around it. (Question relevant to main problem) (a)What is the magnitude of the electric field at point P, which is on the positive x-axis at x = 35.0 cm...