Test Definition and 1000 Threads

Hi, I am using thie χ2 test to fit a dataset in order to calibrate a sensor. \chi^{2} = \sum_{i}{{\left(y_{i} - (a_{0}+a_{1}*x_{i}+a_{2}*x_{i}^{2})\right)^2 \over \sigma_i^2}} The sensor delivers raw data x_{i} and the reference values y_{i} are measured with an instrument of far...

How much blood is lost when getting a blood panel and how long does it take to replenish?

Homework Statement Hi, I'm trying to prove the p-series test, using the integral test. Everything seems to work out fine until I get into this point: Consider when p≠1 (p=1 is easy to see that it diverges, so I will ignore that one). Then we have: ∫(n)^(-p) dn = [ 1 / (-p+1) ] *...

Homework Statement Ʃ (1+n+n2)/(√1+n2+n6)) n=1 to infinity Answer is divergentHomework Equations Comparison Test / P Series 0≤an≤bn The Attempt at a Solution Hello, I simplified the problem to Ʃ (1+n+n2)/(1+n2+n6)1/2 Is it incorrect of me to say immediately right here that because the power...

Seems a real shame, apparently a control fin was faulty. http://www.bbc.co.uk/news/technology-19277620

Significant test! please help I have two questions. 1) if two sets of data have different sample numbers, then can we perform any significant test (e.g., anova, tukey had) to see whether there is a significant difference between the two sets of data? 2) This is a totally different question...

Experiments show that cosmic ray muons reach Earth surface in greater numbers than they should, unless relativistic time dilation is taken into consideration. It also seems to confirm the SR formula mathematically. However, looking at a lot of different experiment records, I have some doubts...

So harmonic series diverges because of the integral test but if I try it on ratio test = (1 / ( x+1 )) / (1 / x) = x / (x + 1) and this is less than 1 so shouldn't it converge?

I was asked this question on a test I just took and I was kinda stumped. I worked it out but I think I did it incorrectly so I was hoping for some input. Thanks. 'A' is a 3x3 matrix and 'I' is the identity matrix for a 3x3. Find the Inverse of 'A' given...

I am doing a simple steel ball drop test on glass to see if the glass passes the standards. We are dropping 1.18 inches (0.535kg) steel ball at the height of 51inches (1.295m). Now, I can calculate final velocity at the impact, but cannot calculate the actual impact force. One of the method...

I read his book "Demon Haunted World" many years ago. I recall that he referred to an experiment where a computer controlled digital readout was placed in a high location not visible to people in an emergency room of some hospital. This display showed computer controlled random words to test...

Are you expected to know all of the trig formulas for the math gre subject test? I don't mean the easy ones, i mean ones such as the sum-to-product or product-to-sum. thanks!

Hey guys, was wondering if anyone could help walk me through this problem. I am fairly sure it converges by the ratio test. Thank you. http://www.wolframalpha.com/share/clip?f=d41d8cd98f00b204e9800998ecf8427e1sgqilv5iv

Calculate the work needed too move a 1.5μC test charge from point B to D. Can someone just check if I'm thinking correctly? Do I just use the formula: W = qEd ? For the E, I calculate the magnitude and direction of the electric field at B. And I use 25cm for the distance and q = 1.5μC

I used to test orthogonality by using the definition MT = M-1, which means I always calculated the inverse of the matrices. However, isn't it true that if M is orthogonal, then MMT = I? If we multiply both side by M-1, we get MT = M-1. Can I use this to proof the orthogonality of a matrix...

Hello, I'm currently at the graduated undergrad level concerning physics and I'm considering eventually doing a PhD in America. Usually this requires a Physics GRE test, which is meant to check whether you have absorbed the necessary knowledge from the undergraduate studies. Good. Well, I...

Here are some questions that I received on my test. I got most of these wrong but I got a couple points here and there. Here are the questions I had trouble with. At the bottom on the questions I tried to solve them but I'm not sure if i did them correctly. Please try and help me because I have...

Homework Statement Determine if the vectors v1=(3,1,4), v2=(2,-3,5), v3=(5,-2,9), v4=(1,4,-1) span ℝ3 Homework Equations The Attempt at a Solution So I first arranged it as a matrix, \begin{bmatrix} \begin{array}{cccc|c} 3&2&5&1&b_1\\ 1&-3&-2&4&b_2\\...

I've been set this question by my tutor and I'm having difficulty doing it. A mass of 2 kg is hung from the lower end of a vertical spring and extends it by 40 cm. The mass is now pulled down a further 20 cm and is then released from rest so that it oscillates about the equilibrium position...

How would you test empirically for the existence of extra curled dimensions of space?

Hi all, Preface: So I have run several series of dynamic torque tests on different size 1/4 turn Butterfly valves. In the test, I am measuring upstream pressure, downstream pressure, valve angle (90° is open, 0 is closed), and torque on a transducer. I know the flow rate, which is in GPM...

I have a data set consisting of ~10,000 patients. Each patient answered how often they had chocolate and we assigned the following values to their responses: Never= 0* 1-6 time per year = 0.01* 7-11 times per year = 0.028* 1 time per month = 0.033* 2-3 times per month = 0.08*...

Do you guys have any strategies to deal with these? It seems that my professor will put oddly worded questions on the exam as a way of weeding out the B's from the A's, and these throw me off, as well as other questions that are very challenging with the same purpose. When I say challenging, his...

Hopefully I'm posting this to the appropriate section. I am trying to figure out a formula for describing the number of possible answer "paths" that may be taken by an individual who is administered a filtered test format. In the filtered test format, the individual must select a passing...

I have a number series ranked from largest to smallest in descending order from 10 - 1. the sample is assumed to be large enough to be normally distributed. If I pick say the 8th number from the top, which statistical test should I use to calculate the probability/C.I that the number picked is...

How do we calculate the P-value from the chi-square test? Is their some formula for doing so? I want to do it by hand and not by some online calculator or application.

I have the princeton review book, and i plan on going through a calculus web tutorial online(mainly for calc 3 stuff). My school library has some pretty good books on algebra/analysis. What other kind of books should i be thinking about getting in order to do well on the test? Also, what...

Homework Statement Two test charges are located in the x–y plane. If q1 = -2.75 nC and is located at x = 0.00 m, y = 0.800 m and the second test charge has magnitude of q2 = 3.20 nC and is located at x = 1.00 m, y = 0.400 m, calculate the x and y components, Ex and Ey, of the electric...

Hello just reviewed some results for someone and thought it was quite odd. Below I have included an example of what was explained to me. Mother: 17,21 Father: 19,20 "daughter": 19,21 "Son": 17,19 By having the mother tested the "Y" chromosome should be capable of being determined...

Homework Statement The quotient test can be used to determine whether a series is converging or not. The full description is in the attachment. Homework Equations The Attempt at a Solution ( i ) Why must they both follow the same behaviour? Even if p ≠ 0, it says nothing about...

Homework Statement Does this series converge absolutely or conditionally?Homework Equations Series from n=1 to ∞ (-1)^(n+1) * n!/2^n The Attempt at a Solution In trying to apply the alternating series test, I have found the following: 1.) n!/2^n > 0 for n>0 2.) Next, in testing to see if...

I just stumbled across this on my own. I find that all leap years in the current calendar are multiples of 16. Therefore, to see if a year is a leap year, one need only to divide the year by 16 and see if there is a remainder. If so, the year is not a leap year. If not, the year is a leap...

Hey everyone! Exam practice, that time of year. In this problem 13 with correct answer C, I'm not sure how they get the test statistic: http://i.imgur.com/doar3.jpgI think they want you to use a F-test, that tests the entire model, which is calculated by: F= ((R^2)/ K)/ ((1 - R^2)/(n-K-1))...

So ye the test begins in 2 months, and i will need to memorize all the phyisc book, its like 300 pages of good ol' physics, conitaining everything everything from electromagnetic induction, alternating current, lasers, wave osscilaitons, sound, em waves etc etc. i would like to ask about your...

While I think that the phenomena of Quantum Entanglement exists, it's real; it's interesting to understand more about it. How does QE/QM explain more mismatches (relatively to simple probability calculations) in Bell's test at wider angles? Or alternatively: Why does/would QE result in lower...

I am not sure if am suppose to consider this charge q, released in the space where there is no friction, or if it is released where there is friction... am I too far from the answer? Because I would assume that it will be in decreasing acceleration. Very confuse with all this topic. Thanks!

Hello everyone I'm new here: So I was about to write some SAS or R to do the following, but now I'm getting old enough to realize most things I think of were thought of before (usually by people way smarter than me). I've done some googling, but I haven't found the golden answer yet. I'd...

I am testing a certain part on a camera. So l was thinking of taking a set of measurements and then change that part and take another set of measurements.After having those two sets of data l wanted to do a chi-square test in order to see if variations in how the two parts perform is due to...

New "loophole free" EPR test with photons by Wittmann et al Recently posted under Recent Noteworthy Physics Papers, https://www.physicsforums.com/showthread.php?t=127314&page=10: Bernhard Wittmann, Sven Ramelow, Fabian Steinlechner, Nathan K Langford, Nicolas Brunner, Howard M Wiseman...

Hi, What does rated output in a transformer signify? Is power same(or almost same) on both sides? In short circuit test, we apply reduced voltage to HV winding so as to circulate rated current in HV. This will cause rated current to flow in LV. But as per definiton of rated current...

If we were to introduced a set of un-entangled, but same polarized, photons as control experiment what would the results be of the control experiment? So we have the following three cases: Bell test Experiment: Send entangled photons Result is that P(-30,30) is not equal to P(0,30) + P...

While studying electricity we always take point charges to calculate force between them according to coulomb's law.And to calculate the electric field around a point charge we take a test charge which is small. My question is: 1.What is the definition of point charge and test charge...

Note: This is not strictly a homework problem. I'm just doing these problems for review (college is out for the semester) - but I wasn't sure if putting them on the main part of the forum would be appropriate since they are clearly lower-level problems.(Newbie) Homework Statement The...

I had a bit of trouble in testing series like this for convergence $$\sum_{ n=1 }^{ \infty } \frac { 1 }{ 2n+1 } $$ If by the comparison test, ##\frac{ 1 }{ 2n+1 } < \frac{ 1 }{ 2n }## for all of n>0, and ##\lim_{ n \rightarrow \infty} \frac{ 1 }{ 2n }## =0, then the series should be...

Homework Statement So fx is how much f changes when you change x. Thus fxx is the rate of change of fx, or geometrically how fast the functions slope is changing. The same can be said for fy and fyy. But what about fxy and fyx? Could someone please explain to me what they mean? I want...

Homework Statement (a)\;\sum^{\infty}_{n=1}\frac{n-5}{n^2}\;(solved) (b)\;\sum^{\infty}_{r=1}\frac{2r}{1+r^2}\;(solved) (c)\;\sum^{\infty}_{n=1}\frac{\cos^4 nx}{n^2}\;(solved) (d)\;\sum^{\infty}_{n=1}\frac{3^r+4^r}{4^r+5^r} (e)\;\sum^{\infty}_{r=1}\frac{r^r}{r!}\;(solved)...

For f(x) = loge(1-x) Clarification: The question isn’t loge(1+x), it’s loge(1-x) a) Find the MacLaurin series: f(0) +f'(0)x + f''(0)/2! + f'''(0)/3!...etc My question is, to what extent do I keep applying the series to, since the series goes on forever and there are no constraints...

Homework Statement I'm trying to determine if Ʃ 1/(3^ln(n)) converges. Homework Equations The Attempt at a Solution The preliminary test isn't of any help since lim n→∞ an = 0. I tried the integral test but I couldn't integrate the function, and I don't think it's the best...

Is it true that only a NMR test is able to detect the effectiveness, quality, quantity of a product? That it is able to detect wrong raw material, over-reaction, or isomers occurring during synthesis? But what about the other tests like GC/MS, HPLC/GC, HCLtitration, meltingpoint test. Is one...

a UK company got $10M to build it, see here http://www.greentechmedia.com/articles/read/liquid-air-for-utility-scale-energy-storage/ . Can this be at least hypothetically feasible or is it more like pure quackery for stupid investors? ETA: to clarify, I don't doubt that it would "work" the same...