Mean Definition and 1000 Threads

I'm trying to come up with a good definition for model: X is modeled means x exists at time 1 and point 1 and has direction y, then it will exist at time 2 and point 2. Of course there are different types of modeling, for example, sometimes particles decay into other particles. Let me...

What is the sample mean of the following matrix?

Hi; According to Wiki the minus sign is a unary operator (a negator). Calculations are done right even if the minus sign is considered to be a (-1) multiplier. How to explain, for instance, -(a+b)=-a+-b if the sign is considered an operator? Thanks...

Hi all, I'm having trouble finding a certain generalization of the mean value theorem for integrals. I think my conjecture is true, but I haven't been able to prove it - so maybe it isn't. Is the following true? If F: U \subset \mathbb{R}^{n+1} \rightarrow W \subset \mathbb{R}^{n}...

We are all familiar with E=MC2, although I don't know how that formula relates to the big bang. In any case, I suspect I don't have the math to understand it and it would probably take several pages to define it. Everyone is familiar with F=MA. What most people don't know is that if you...

Hi all, I'm trying to calculate the M.A.P.E. using the accuracy() function in SDMtools. I have an output of 10.69. I'm not sure if this is 10.69% or 1069% as previously in a different model I had gotten an output of 0.34. If anyone is familiar with this, I would appreciate any help...

Homework Statement Showing all your working, calculate the arithmetic mean and standard deviation of the number of days lost. Table shows man days lost to sickness.. Days lost: 1-3 4-6 7-9 10-12 13-15 Frequency 8 7 10 9 6 Homework Equations...

Let X(bar)[sample mean] be the average of a sample of 16 independent normal random variables with mean 0 and variance 1. Determine c such that P(|X(bar)| < c) = 0.5 Ok here's the problem, I know this is SUPPOSED to be a simple computation but for one reason or another little ol' fooliosh...

1. Homework Statement a) Calculate the theoretical diameter of pipe, nominal pipe diameter and mean velocity of nominal pipe diameter. Maximum velocity = 1.8m/s Q(vol. flow rate) = 0.01M^3-1 b) Find the Reynolds number for the process and then the head loss due to friction, state any...

I'm reading Georgi Shilov's Linear Algebra and at the bottom of page 10 is has an equation a_{ij}=\lambda b_i+\mu c_i +\ldots +\tau ?_i Where the ? is there is a symbol that I don't know. It looks like a curly lowercase f (like an integral symbol with a short stroke through the top part). It...

what does position entangled mean (physically)? The below is an attempt to understand position entanglement. It may require a lot of corrections and modifications. Look forward to your responses. A photon (A) would have a probability distribution, so would it's entangled twin/photon (B). The...

Hi! I do have this problem - Consider that for a set of values, I do have a Poisson distribution with mean value <m> - Now, I need to gather another set of dataset, which I should vary the mean value by 5% - My question is, how can I translate each one of these new values to sigma deviations...

I'm trying to make a MATLAB plot with two types of data, i.e. temperature and air flow rate. Since the temperature and air flow rate are on different scales I wanted two y-scales and since there are quite some data sets, I wanted to make the two air flow rates bold. I tried this, but it doesn't...

What does the word "action" mean in quantum physics? Hi everybody, I was reading about the application range of quantum mechanics. I found the effects of quantum mechanics are negligible where the action is on the order of the Planck constant. But, What does the word "action" mean? Thanks

What does it mean: "transforms like a vector" Reading Zee's new "Einstein Gravity in a Nutshell" I just don't get it what exactly is meant by "transforms like a ...". He explicitly writes that not any odd column of numbers is a vector, so I am trying to figure out what exactly is meant. Here is...

ive only studied up to calculus 2, and have never encountered ∏, but from what i believe it means, it is a multiplier. much like summation but instead of adding things together they are times'd together. is this correct? and also can i see a example? thank you :)

If one has the mean and standard deviation of a population, is it possible to calculate (or estimate) the mean and standard deviation of the inverse population (ie. 1/(every value in the original population)? Thank you!

I haven't studied quantum physics academically and I have no understanding of it mathematically so forgive me if my questions are strange, nonsensical or erroneous. For instance in the double slit experiment when we attempt to observe the object going through a slit then the diffraction...

Can the arithmetic mean of a data set of complex numbers be calculated? if so, can the method be demonstrated?

Hello, Does anyone know why we use the root mean square of the relative velocity in calculating the mean free path? As is done in this example: http://galileo.phys.virginia.edu/classes/152.mf1i.spring02/MolecularCollisions.htm Seems like it would make more sense to find the mean of the...

So this is a fairly simple conceptual question: can you estimate/compare the mean free paths for individual components of a mixture of gases? I'm primarily looking at the equation given here and the information accompanying it. Consider the case where we have several individual, separate...

Hello, I've been trying to find online where I could calculate my grade based off a college curve. So the average grade on the test was a 63. The RMS is 16. I got a 86. So what will my grade curve to? This is out of 50 people. Also, the professor curves to a 70 (I think).

...curvatures in spacetime being created by Earth's gravity? My understanding is that its speed offsets the gravity being created by earth, that it's freely falling towards Earth but never hits it because its speed somehow causes it to keep missing. If that's the case, wouldn't that suggest...

Homework Statement Metric ansatz: ds^{2} = e^{\tilde{A}(\tilde{\tau})} d\tilde{t} - d\tilde{r} - e^{\tilde{C}(\tilde{\tau})} dΩ where: d\tilde{r} = e^{\frac{B}{2}} dr Homework Equations How to calculate second fundamental form and mean curvature from this metric? The Attempt at a...

Hi forums. I have what I think is a simple question but I'm making myself confused. I'm trying to work out the relationship between energy density ( u = energy per unit volume ) and temperature in a multi-species ideal gas (no molecules just different mass ions). The simplest example of...

I found this in Srednicki's QFTbook. I don't know what ↔ means. Help me, please

Homework Statement Two waves travel in opposite direction form a standing wave of y= 2sin(31.42x)cos(7854t). Find the positions of first two nodes with x>0. Homework Equations The Attempt at a Solution The question didn't say whether the standing wave starts from node or...

So in finding a pattern for the nth derivative for y = x-1 the book wrote y(n)(x) = (-1)nn!x-n-1 What does the exclamation mark mean? I know != means not equal to.

Homework Statement find dy/dx for the function xy^2+xlnx=4y for x>o Homework Equations xy^2+xlnx=4y The Attempt at a Solution I found the dy/dx to be "(y^2+lnx+1)/(4-x)=dx/dy" What is it asking me to do with the x>0? Do they want me to plug in a value greater than 0 for x and solve for y...

Hi Guys I normally post over on the Quantum Physics subforum and over there the question came up of if a probability of 1 means a dead cert. I am pretty sure Kolmogrov's axioms imply it but another person wasn't so sure. Here is what he said: 'I think it will be easier to explain this by...

I am not able to understand how to go about this problem: Find the minimum mean square estimator for the scalar parameter w based on the scalar observation z = ln w + n where f(w) =1 if 0<=w<=1; 0 else: and f(n) =e^-n if n>= 0; 0 else I did f(z/w) = (f(n))...

I am not able to understand how to go about this problem: Find the minimum mean square estimator for the scalar parameter w based on the scalar observation z = ln w + n where f(w) =1 if 0<=w<=1; 0 else: and f(n) =e^-n if n>= 0; 0 else I did f(z/w) = (f(n))/ g'(n)...

So I tend to here something like "(insert famous scientist) mastered calculus at the age of 13". What exactly is that suppose to mean? Surly you can be good at a subject and get an A in the course, but still be far from a master. To those of you who are pursuing higher education or especially...

The book Orbital mechanics by Curtis says that the function (I labeled M2evals) is monotonically increasing. However, at pi, I have a discontinuity and the graph jumps below the negative axis when it should continue on; that is, the e = 0 should be the line y = x. import pylab import...

I have been following Quantum Cosmology since Hawking's A Brief history of Time first appeared. That inspired me to attempt to drill down to the technical papers involved. I also made use of the book by Hawking and Penrose, The Nature of Space and Time. Very broadly speaking there seems to be...

I was taking a test and basically for the answer I had limited it to two choices. A: x=3 and x does not equal 2 or B. x=3 x=2 When I plug in three, I got 3/1=12/4 so three is true. But when I plugged in two I got 3/0=8/0 So would this be true too? Or does x not equal 2? Wouldnt...

eg. Find the directional derivative of the function phi=xyz^2 at the point (1,2,3). Actually what is the math used for? Let's say phi is the temperature of air(scalar field). ∇phi will be the rate if change of temperature at (1,2,3), why the direction come out. directional derivative of it...

Air Compressor: What would "twin-cylinder" mean? I'm figuring out details about an old compressor and it's made by a Greek Company. I can't find too many details but one part that confuses me is it says "twin cylinder". Picture below. Specs say: Oil lubricated twin-cylinder...

Given that a photon of known wavelength is emitted when an electron goes to a lower energy state, if there are only so many different types of atoms, and only so many electron orbits around those nuclei, the number of wavelengths possible is finite: If true, then the EM spectrum is quantised...

I know lots of people say that when you are learning something it is better to understand it rather than just blindly try to memorise it. This might be a silly thread, maybe I'm thinking too hard about it but I would really like some clarification. So I'm wondering, what does it really mean...

Homework Statement State the Mean Value Theorem and find a point which satisfies the conclusions of the Mean Value Theorem for f(x)=(x-1)3 on the interval [1,4]. 2. The attempt at a solution Mean Value Theorem:states that there exists a c∈(a,b) such that f'(c)=\frac{f(b)-f(a)}{b-a}...

Why is brake mean eff.pressure higher at max.Torque than max.power?,I am looking for an explanation in terms of equations,since I already know the theoretical reason i.e at Max.Power→the rpm is at Max for the engine →the friction losses are maximum→bmep at max power is lower than at max.torque...

Let X1, X2, X3 be three random variables. Suppose all three have mean μ and variance 1. The sample mean is Y = (X1 +X2 +X3)/3. (a) Can you compute the mean of Y? If so, what is it? If not, why not? I have that it is either μ OR that it is not possible to find, since we don't know if they...

Homework Statement Let f(x) be a continuous function on [a, b] and differentiable on (a, b). Using the generalised mean value theorem, prove that: f(x)=f(c) + (x-c)f'(c)+\frac{(x-c)^2}{2}f''(\theta) for some \theta \in (c, x) Homework Equations Hints given suggest consdiering F(x) =...

Hello. I have a problem with one task. The task is: Suppose that you playing the game. You have n moves. on each move you win the game with probability p. Your winning amount is equal to move number. For example if you win in first move your winning amount is 1, if you win in n move, your...

Hi, this is my first time posting on these forums but I've been reading them for a while. I was having a look at metamaterials and it mentioned that metamaterials had negative permittivity and negative permeability. I also found that metals naturally had negative permittivity; though I am...

If at 120 K the Vrms is v , then at 480 K it will be a. 1 b. 2 c. 3 d. 4 Which formula is to be used here? Plz solve this.

Also how can local causality be violated?

What does "aqueous workup" mean? I'm taking a second year organic chemistry and it's a slightly advanced level but I didn't take the 1st year advanced level org.chem. so I may have missed a couple of common terms. What I don't understand is what does workup mean? At the end of some reaction...

Hello I was trying to solve this sample problem, but I really don't get it. The book says this word by word: The equation sin3x=1 implies 3x=(pi/2)+2kpi, k an integer. x= (pi/6)+(2kpi/3), k an integer *Divide each side by 3. Because x is not restricted to a finite interval, the given...