deviation Definition and 388 Threads

In the book "The mathematic of Gambling", the author considers a fair coin with 50% getting head and 50% for tail. The expectation of such coin, of course, will be zero. Here is what I read from the text, it reads Consider the fair game example mentioned earlier in the chapter (fair coin)...

Let's say I monitors my local aquifer (Edwards) using well J-17 over the past 8 summers (not counting this summer). I found that the mean water level/day is 680 ft above sea level, with a standard deviation of 30. Assuming a normal distribution, how do I find the probability that the aquifer...

Homework Statement I have two sets of data, each with 30 distances and 30 results, I have the mean, median, mode, range etc, I have drawn histograms and cumulative frequency curves, got the IRQ for both sets of data. Now I need to compare the data using standard deviations and also find...

How to compute \beta = arg min_\beta \sum_{i=1}^N {|y_i - x_i^T \beta|

What does this mean? Average? Sum?

OK I was going to post this in homework, but it's not homework (left school a long time ago ;)) Anyway when I was at school I did not do stats I did mechanics instead (you had a choice). However all the people doing stats were always on about the the SD, which was a bit annoying cos I...

Homework Statement Hi, my teacher asked me to conduct an experiment on the question "How does the angle of deviation depend upon the angle between two mirrors?" - We weren't given much else on the topic. I know how to find the angle between two mirrors, but finding the angle of deviation of...

derivation of an expression for the angle of deviation in a prism, in terms of \thetaa and \thetag and A Homework Equations (\thetaa - \thetag ) + (\thetaa' - \thetag' ) = D A = \thetag + \thetag' i get stuck trying to put \thetaa' into the terms the question states, anyone have an...

I would like to understand the theory behind the standard deviation formula. The way it was explained to me, you have to subtract each value from the mean and square it to avoid the negatives canceling out the positives. After multiplying and dividing by the correct frequencies, we have to...

[b]1. A voltmeter is used to measure a known voltage of 100V. Forty percent of the readings are within 0.5V of true value. How do I figure out the standard deviation of the voltmeter, and how do I figure out the probability of an error of 0.75V? [b]2. I am trying to figure this problem...

Deviation in the direction of current... Is there any law of refraction of direct current lines at the boundry between two conducting media relating with conductivities and the angles between the current lines and the normal of the boundry surface..?

Hi there, I'm trying to understand the derivation of geodesic deviation given here: http://wps.aw.com/wps/media/objects/500/512494/supplements/Ch21.pdf but I can't figure out why x(t)+\chi(t) obeys the geodesic equation (eq.(7)). Of course x(t) does, since it is per definition a...

Homework Statement A ray of light is incident in air at an angle of 40 degrees to the normal to one face of a 60 degree glass prism. Calculate the angle through which the ray has been deviated by the time it emerges from the prism. (refractive index of glass wrt air is given as 1.50)...

Hello Anybody know how we can solve the equations of geodesic deviation in a given spacetime whether approximately or exactly? Thanks in advance

Homework Statement Sally, Bob and Charlie each measure the period of the same pendulum to determine the acceleration of gravity, g. The lab instructions say that you should determine the period by timing the time of 100 swings (complete cycles) of the pendulum. Sally is the first to do the...

Homework Statement Students measured an object 5 times, and got the results 11,25 cm, 11,20 cm, 11,22 cm, 11,18 cm i 11,25 cm. The height of this object is: A. h = (11,22 ± 0,03) cm B. h = (11,22 ± 0,04) cm C. h = (11,25 ± 0,07) cm D. h = (11,25 ± 0,03) cm Homework Equations Standard...

light enters the side of an equilateral crown glass (1.62) prism at an angle of incidence of 35deg determin the angleof deviation after it has passed through the prism i don't know what equation I am supposed to use i got the angle of refraction into the glass that is 20.74deg but i don't...

Homework Statement Homework Statement Hello everyone! I have been having trouble with cumulative frequency graphs in excel for some time now. I wonder how you make the "bell graph" or cumulative frequency graphs or standard deviation graphs in microsoft excel. I have excel for mac. I...

Given an imaginary, mechanical chimpanzee that never wears out nor sleeps nor relents. Who is compelled to type constantly through eternity into an endless text file using a US standard keyboard... as fast as he can. That this monkey knows simply that he must hit only character keys and only one...

By definition standard deviation has divisor 'N' . But in Microsoft Excel the "STDEV" function gives 'N-1' as divisor. This may not be major issue to many of the people. But the command "STDEV" makes many users feel that this is standard deviation, i.e. it has divisor 'N'. Misleading...is...

The problem is to find a closed form for the expectation (mu) and standard deviation (sigma) of the probability density function underneath (Maple notation): f(t) = a*exp(a*t)*BesselK(0, 2*sqrt(exp(a*t)))/BesselK(1, 2) I was able to find an expression for mu:: mu =...

i would post this in the chem section but more people view this one.. im having a quiz on standard deviation in chemistry lab onf riday, and I am not sure AT ALL how to do this. i tried asking the teacher but he's not to good at explaining. and i tried lookinga t the difficult to understand...

Hello! Quick question: Is this valid: (\frac{standard \left \left deviation}{average} * 100)? The standard deviation is just a measure of the spread of the data from the average, so by doing the above, is it retaining its 'representation' as a measure of spread, just as a percentage of the...

First of all: Sorry about my English, but I am from France ;-) The problem: Somebody shoots into a block which is put up on two free running ropes and now you want to determine the velocity of the projectile by measuring the deviation of the block. I also have to consider gravity, which may...

I need to calculate the average time of an event, and I'd like to calculate standard deviation as well. The problem is - there is no such thing as negative time - zero is a boundary - so how does it make sense if the average is 4000us (microseconds) and the stdev is 5000us? Is there a...

Homework Statement Possible reasons for a deviation from the accepted value for acceleration due to gravity in a vacuum are Homework Equations No real relevant equations The Attempt at a Solution • Wind • Atmospheric pressure • Air density • Shape of the objects • Size of...

Homework Statement A vertical building was built on a horizontal plane. The plane is then tilted to A=(0,0,0) B=(1,2,0) and C=(0,3,1). By what angle (in radians) does the building now deviate from the vertical? Homework Equations Dot Product Cross Product The Attempt at a...

Homework Statement http://img338.imageshack.us/img338/5064/picture1nk.png 2. The attempt at a solution I know the area for -1.5 is .0668. I also know that the area of the positive half of the curve is .5000. I don't know how to figure out what the other blue piece is or how much the white...

A deviation from General Relativity? [/Color] Reference: http://arxiv.org/pdf/0909.3853v2" http://www.newscientist.com/article/mg20427314.400-rethinking-relativity-is-time-out-of-joint.html" http://arxiv.org/pdf/0811.4684v2"

Hi, can someone just confirm that to get the GSD of a distribution, I simply take the natural log (or log 10?) of all the numbers then find the arithmetic standard deviation of that? Thanks :)

The mean and standard deviation of a random variable x are -11 and 4 respectively. Find the mean and standard deviation of the given random variables: 1) y=x+7 2) v=8x 3) w=8x+7 2. Homework Equations : E(x) = u, E(ax+b) = aE(x)+b The Attempt at a Solution I've gotten...

Homework Statement It has been projected that the average and standard deviation of the amount of time spent online using the Internet are, respectively, 14 and 17 hours per person per year (approximately normally distributed). What value is exactly 1 standard deviation below the mean?Homework...

Okay... this is a really simple question but I am pratically going nuts over it I can't sleep, I've been looking at it for like 12 hours, googling and wiking over it I am going crazy... Okie... Suppose I have 4 numbers, 0, 2, 4 and 6 and I grab 2 random ones with replacement... so I have...

The uncertainty is interpreted as standard deviation, then does it mean uncertainty principle only has statistical meaning? I mean, is the principle only meaningful when a particle's momentum and position are measured simultaneously by many detectors?

Wikipedia gives an extensive amount of vector identities: http://en.wikipedia.org/wiki/Vector_calculus_identities http://en.wikipedia.org/wiki/List_of_vector_identities Does anyone know of a link where most of these are proved. I'm particularly interested in the product rules but would...

Homework Statement Mean value and deviation of momentum for this wave function: \Psi(x,0)=cos^2(kx/L)e^{2ikx/L} Homework Equations The Attempt at a Solution I express the cos^2 in terms of exponencials: \Psi(x,0)=(1/2)+(1/4)e^{2ikx/L}+(1/4)e^{4ikx/L} the momentum of...

http://en.wikipedia.org/wiki/Jacobi_field also see http://iopscience.iop.org/0305-4470/14/9/029/?ejredirect=.iopscience What's the difference between the jacobi equation and the geodesic deviation equation?

Hello, I seriously need some help as I can't figure out what to do here. I am working on coding a vaccination simulation that measures rates of infection for period of 100 days. I have this variable delta, which is the number of days the infection period lasts. Delta is 5, or at least on...

I am an independent researcher ready to compile data from an experiment. I have a set of measurements that include the uncertainties of measurement. If I calculate the mean for the set (and thus the standard deviation) do I need to include the uncertainties when doing this calculation?

Optics, prism and angle of deviation 1. Angle of incidence, emergence and deviation are respectively 30, 60 and 45 degree. 2. 3. I think that it is irrespective of the refractive index.

I'm new to studying statistics but it seems to me like standard deviation and kurtosis measure the same thing. The higher the standard deviation, the more spread out the data is, while the lower the kurtosis the more spread out the data is. I'm sure I'm wrong about this so can someone help...

I am a little confused about the justification behind what we do with things we believe to be poisson distributed. Take for instance, gamma-decay counts from a scintillation detector. Suppose we got 100 counts using a 1 minute integration time. We would then assume that the distribution of...

I went for a lecture and the lecturer said that the square of the difference between the x sub i and the mean is the take precaution of the negative value. This has been bugging me , i was wondering why don't they just take absolute because there is a difference between ...

What are the advantages of using the absolute mean deviation over the standard deviation. Is it possible to show a simple example where the former is more (or less) appropriate? Also, related to the mean deviation is my own variation. Does it have a name? Instead of calculating the absolute...

Hello again, I have a question here that asks me to find how large a sample size is, but I have no Standard deviation. How would you tackle this> How large a sample size do we need to estimate the mean annual income of natives in New York, correct to within $1000 with probability 0.99? No...

Homework Statement Given some data set, (x,y), fit to the the curve y=bx^2+a by minimizing the square of the deviation. Preferred to use matrices. Homework Equations The deviation for the ith data point is simply: d_i^2=(y_i-y)^2=(y-bx_i^2-a)^2 The Attempt at a Solution If I understand...

I am comparing two RMS error time-series and I would like to generate error bars on the RMS results. I think the RMS error is a standard deviation of an assumed zero mean process, and I have the gut feeling that this should be the standard deviation of the sample standard deviation. Is that...

1. An airline's flights have a mean arrival time of 5.8 min late with standard deviation of 2.1 min. What would be the appropriate x - scale for a histogram? 2. http://www.mathsrevision.net/gcse/sdeviation2.gif 3. I tried to do this problem, but I couldn't think of anyway to find...

Homework Statement A health physicist is testing a new detector and places it near a weak radioactive sample. In five separate 10-second intervals, the detector counts the following numbers of radioactive emissions: 16, 21, 13, 12, 15. a) Find the mean and standard deviation (SD) of...

Homework Statement 1) A random sample of 26 students who are enrolled in College A was taken and their SAT scores were recorded. The sample mean is 548 and the sample standard deviation is s=57. Assume population is normally distributed. a) Find a 98% confdience interval for the standard...