deviation Definition and 388 Threads

hello, how can i find out the angle of deviation for plano-concave lenses. thanks

For some given statistics (e.g. Fermi-Dirac or Bose-Einstein), once we know the average number of particles at state r, it is easy to calculate the dispersion by calculating \overline{(\Delta n_r)^2} = -\frac{1}{\beta}\frac{\partial \bar{n}_r}{\partial \epsilon_r} and the total number of...

Homework Statement I am doing a chemistry lab and I am going to be commenting on the precision of my data in my report I figure that calculating the mean deviation is the best way to do that. I had 6 separate trials in this experiment. I have already calculated the mean which is the same as...

Homework Statement Data set in X with mean xbar = 100 and standard deviation Sx = 10 Find ybar and Sy for 2(Yi-5)/10 + 7 Homework Equations The Attempt at a Solution All the problems I have seen are in the form yi = axi + b in which case the mean ybar = a(xbar) + b and...

Homework Statement The resistances of 50 resistors are measured and the results recorded are as follows: Resistance x Frequency 1.) 5 x 17, 2.) 5.5 x 12, 3.) 6 x 10, 4.) 6.5 x 6, 5.) 7 x 5) Calculate standard deviation of the measurements Homework Equations The...

There are two things I don't understand here: Firstly, why in the standard deviation expression we use the Q operator instead of the Q value itself? Writting Q seemed more natural and then in the next expression I would just stick the corresponding operator. Which would lead to the same result...

Much to the annoyance of my boyfriend, I have this deviation that I like to watch 'make-over' programs (Next top model, Project catwalk). I just watched another such episode (Looking Good), but seeing someone transform like this is just fun to watch (and it is not over the top like some of the...

hello can anyone explain what the difference is between RMSE and standard deviation. I am using RMSE in multivariate analysis but is it just the standard dev. why another name?

What is the formula for standard deviation?

Hey guys, Just a question which has been puzzling me for some time. I am told that means of samples of a population can be normally distributed with mean of \mu and with standard deviation of \sigma/\sqrt{}n Can someone please explain to me how the standard deviation is derived or is it...

Homework Statement The scores on an exam are normally distributed, with a mean of 77 and a standard deviation of 5. What percent of the scores are greater than 87? Homework Equations The Attempt at a Solution I don't understand what it is exactly that I have to do to get the...

Homework Statement Due to the expense involved, car crash tests often use small samples. When 5 BMW cars are crashed under standard conditions, the repair costs (in dollars) are as shown in accompanying list. Use 0.05 significance level to test the claim that the mean for all BMW cars is...

Hi I am reading a popular physics book. It discusses the test of Einsteins theory by Eddington at the eclipse. "The deviation of the light was double that predicted by Newton's physics" Why does classical physics predict any deviation of light by gravity, did light have a mass in...

Hi, You know famous equation, \frac{d<A>}{dt} = <\frac{i}{\hbar}[\hat{H},\hat{A}] + \frac{\partial\hat{H}}{\partial t} > But liboff said if \frac{\partial \hat{A} }{\partial t} = 0 then, \frac{d<\hat{A}>}{dt} = 0 this is the proof \frac{d<A>}{dt} =...

Homework Statement Recalling that k=R/Na (Na is Avogadro's number), show that the density of fluctuations of an ideal gas are given by : <(dp)^2> / p^2 = 1 / (N*Na) where p is the density (mass/V) That is, the relative mean square density deviation is the reciprocal of the number of...

1. Homework Statement The alpha particles used by Rutherford had a kinetic energy of 7.7 MeV and, for a head-on collision would get to within a distance of 3×10-14m of the centre of the gold nucleus. However the actual radius of a gold nucleus is approximately 7×10-15m. 2. Homework Equations...

If the gravitation has very very tiny deviation from inverse square law！our solar system became unstable? If so ,how long people on the Earth can notice it? Thank you in advance!

If the gravitation has very very tiny deviation from inverse square law！our solar system became unstable? If so ,how long people on the Earth can notice it?

Hello, The standard deviation is calculated as: http://www.mathsrevision.net/gcse/sdeviation2.gif Now the problem I have is that how you calculate the standard deviation (more accurately?) over both samplesvif you have two samples of different size, n1 and n2, in which the level of the...

Homework Statement If there are 4 children in a family, find the probability of getting exactly 3 girls. Find the mean, variance, and standard deviation. Use two different methods(binomial distribution method and general probability distribution method). Homework Equations Binomial...

"Normalizing" standard deviation between two data sets I have a baseline set of data collected which has a standard deviation of X, and then I collected another set of the data under a different condition (different temperature), and this has a different standard deviation Y. How do I cancel...

Homework Statement Suppose that 40 and 90 are two measurements of a population data set and that their z-scores are -2 and 3, respectively. Using only this information, is it possible to determine the population's mean and standard deviation? If so, find them. If not, explain why it's not...

Hi guys. Im new at this site so please be nice to me =P. I've been working on some practice papers for my upcoming end of semester exams. Cant get these two questions out ><. Any help is greatly appreciated Thanks in advance jenny xoxo 1. A sample of 28 students measured their...

hi all, i kind of have a black hole regarding my understanding of the consistensy of tidal forces and geodesic deviation analysis. one can determine some coefficients of the riemman tensor from the tidal forces equations, by getting to a form that is like the form of the geodesic deviation...

Hi, I'm just trying to find out if there is a calculation to that relates deviation from a straight line to the forward velocity and the rotation of a circular object. Essentially i have a small project that i get to prepare and work on and was thinking of trying to find the optimal bowling...

Given the mean energy of a system in a heat bath is \bar{E} = - \frac{\partial ln(Z)}{\partial \beta} Where Z is the partition function and \beta = k_BT Why is the standard deviation of E defined by: (\Delta E)^2 = \frac{\partial^2 ln(Z)}{\partial \beta ^2} I can't seem...

Standard deviation and mean - "combining" the two Lets say one was to have a range of data, with the mean and standard deviations for the different subsets of data. The "best" subset is that with the lowest mean, however how do I include the standard deviation when making my decision. For...

Homework Statement Problem 1.2 from the book Introduction to Quantum Mechanics (2e) by Griffiths: Suppose a rock is dropped off a cliff of height h. As it falls, a million photos are snapped, at random intervals. On each picture the distance the rock has fallen is measured. a) Find the...

This might be embarrasingly easy or impossible; I've been a computer programmer for too long since my statistics classes to tell for sure :blushing: I have a set of records with the following data for each record: interval, mean speed, standard deviation of speed, number of observations...

Hey i was wondering if anyone could help me with this question at all? I don't have a clue about the calculations and would be grateful if it could be explained to me! I'm really struggling! Thanks Some light emitting diodes are tested and a sample is found to have a mean lifetime of 2048...

but only knowing the previous standard deviation, the previous mean (and the sample to be removed). does anyone know how to do it?

Hi, How can I rigorously prove that the quantity S = \sum_{i=1}^{n}|X_{i} - a| (where X_{1},\ldots,X_{n} is a random sample and a is some real number) is minimum when a is the median of the X_{i}'s? Thanks.

Write a program to find and display the Largest, Smallest, Average, standard deviation and the Sum of all numbers entered from the keyboard.The data entry should end with a Sentinel Value. After finishing ask if the user wants to continue entering new set of numbers or not. , where X...

Hey guys, i have two question that me and a couple of my mates couldn't figure out for the life of us in class so i bring them here. The first one at first glance seemed fairly easy Homework Statement Calculate the angle of deviation at a glass air interface for an angle of incidence of...

In doing a problem, I considered N (a large number, in the range 100,000-1,000,000) raindrops, falling into A (fixed at 100) segments on a roof, distributed using a random number generator I programmed. In considering the number of raindrops that fell into a given segment, the average would be...

I ran across an interesting statistic today while doing some research, but it was stated as a matter of fact without explanation and there appears to be a dearth of material on it. It was stated that the Mean Absolute Deviation ("MAD") of a Normal (Gaussian) Distribution is .7979 of a Normal...

Hi...does anyone have a good description (or a link to it) on geodesic deviation equation?Most of the references i have are in a setting of relativity, which make me all at sea. Please help me if you know a mathematical characterization of how geodesics from one point deviate (which just...

[SOLVED] Quick question about finding standard deviation Now I know that \sigma=\sqrt{var(x)} which simplifies to this expression : \sigma=\sqrt{\frac{1}{N}\sum_{i=1}^{N}(x-\overline{x})^2} can someone show me how they got such an expression? and in chemistry I have to use a standard...

Homework Statement For this set of data find the mean and standard deviation Temp...# of days 90-94...1 85-89...3 80-84...6 75-79...12 70-74...7 65-69...1 2. The attempt at a solution I don't know how to find the mean or standard deviation when the data is divided into...

Homework Statement The mean height of players in a basketball competition is 184 cm. If the standard deviation is 5 cm, what percentage of them are likely to be: a) taller than 189 cm b) taller than 179 cm c) between 174 cm and 199 cm d) over 199 cm cm tall? Homework Equations...

Hi all. If I have a function V(x1,x2,x3,x4) and I want to calculate it's standard deviation when x1,x2,x3,x4 are standard normal and their variances are small, then formula (8) on this page http://www.devicelink.com/mem/archive/99/09/003.html" is an approximation to the standard deviation...

For sets X and Y, is it true that s_{XY}=s_{X}\overline{Y}+s_{Y}\overline{X}, where s represents the standard deviation and XY is the set containing x_{i}y_{i}?

Read gambling problem/Standard deviation Posted: May 23, 2007 4:57 AM Click to edit this message... Click to see the message monospaced in plain text Plain Text Click to reply to this topic Reply I'm analyzing some data from online gambling sites.I'm trying to prove they are...

Hi, I was trying to solve this question but my answer is different to the one given by my textbook. "The weight of a randomly chosen plastic washer is normally distributed with mean 5g. Calculate the standard deviation in grams given that the probability that a randomly chosen washer weighs...

Very basic question which has confused me: if the variance of an expectation value <A> is: uncertainty of A=<(A-<A>)^2>^0.5 how is this equal to: (<A^2>-<A>^2)^0.5 ??

I wrote a program that is supposed to find the standard deviation of a set, but something really strange happens in a for loop that I have in my main function. int main() { int i=1; int NUMBER_OF_ELEMENTS; double data[NUMBER_OF_ELEMENTS]; cout << "Please enter the number of...

Can someone explain how to derive the formula for geodesic deviation? i didn't quite understand it. I'm using schtuz's book.

Standard Deviation Problem in Physics. Help!? Homework Statement In working with Wheatstone bridge one student chose the value for R1 so that the bridge is balanced at L1 = 48.5 cm and L2 = 51.2 cm. If Each measurement has an uncertainty of +/- .05, what would be the minimum value for the...

Homework Statement In a recent survey, 80% of the community favored building a police substation in their neighborhood. If 15 citizen are chosen, what is the standard deviation of the number favoring the substation? Homework Equations I know that my mean is 15 and the probiblilty is 80...

% Deviation vs. % Error?? Hey guys, what's the difference between percent deviation and percent error?? I'm totally confused... how do I compare those two percentages? Any explanation or links that can help me with this so I can understand better is much appreciated! Thanks~ Rachelle