What is Test: Definition and 1000 Discussions

Homework Statement The following data is hypothesized to possesses a normal distribution, is that hypothesis sustained by a Chi-square test at .05 significance: <66...4 67-68...24 68-70...35 70-72...15 72-74...8 >74...4 The Attempt at a Solution 1. I know that I should...

Is there an easy way to see if a unitary group is cyclic? The unitary group U(n) is defined as follows U(n)=\{i\in\mathbb{N}:gcd(i,n)=1\}. Cyclic means that there exits a element of the group that generates the entire group.

Hi everyone, I'm looking into building a test bench in my garage, as currently my parts are strewn about my kitchen table and computer desk. I'm mainly going to be working with my Arduino and doing computer building/electrical repairs, maybe some PCB etching once I learn how. So far I'm...

I'm sorry - I know this is archived somewhere around here but I couldn't find it ... Can anyone give me a link for the set of tests used to identify a crackpot (either the theory or its author). I've forgotten who had it on his website - someone at Princeton, maybe?? I've got a live one on...

Hello, I am writing up (for some other students) our lab's inversion method for viscoelastic media. I want to use some test functions for simple illustrations, side by side with the actual inverted images. I can write simple test functions for elastic waves that come out perfectly -- all...

how are cdf and pdf related in statistics? please help i have a test tomorrow

help with practice test problem! curved rod with charge density?? Two plastic rods are curved. The left rod is a 120° circular arc of radius R, and has uniform charge density λ. The rod on the right is a 120° circular arc of radius 2R, and has uniform charge density -2λ. A point P is located...

I have a physics test in a week and am having trouble coming up with the proper equations to solve the problems. Does anybody want to offer hint or guidelines to solving these? I have been working on these but I don't think I am approaching the questions appropriately. 1) A 920-kg sports car...

Help with this confusing circuit! test tmrw! Find i across resistor. http://imageshack.us/photo/my-images/202/circuitu.jpg/ my teacher lectures to fast and i don't understand the notes i put down. can someone explain this one to me please??

I have designed a test apparatus where I can apply known bending and torsion loads to thin sheets of foamed plastic. All test samples will be identical sized sheets with various treatments to improve stiffness..with the added weight of the treatment recorded. I will use the information to...

I know that there are many web-sites that explain Pearson's chi-square test, but they all leave the same questions unanswered. First, to make sure I have the definitions right: 1) for a fixed population with standard deviation σ,a fixed number of degrees of freedom df=k, and a fixed sample with...

I was looking up info on this topic and came up with this article (http://eng.sut.ac.th/metal/images/stories/pdf/Lab_7Bend_Eng.pdf)... what I don't get is why it says that bending test for ductile materials isn't good. "The stress is essentially zero at the neutral axis N-N. Stresses in...

When discussing the second partial derivative test in multivariate calculus, a reference is usually made to an elusive "higher order test" that one must defer to in the case that the second partial derivative test fails. Does anyone know the general form of these higher order test? My first...

Homework Statement A few examples done in class that I didn't understand are as follows: (Find out if convergent or divergent) integral 0-->infinity ( x / (x^3 + 1) ) integral 1-->infinity ( (2+e^(-x) ) / x ) Homework Equations None The Attempt at a Solution Basically, I have NO idea...

Homework Statement Using the limit comparison test to determine convergence or divergence (1) \sum^{\infty}_{n=1} \frac{(ln(n))^{3}}{n^{3}} (2) \sum^{\infty}_{n=1} \frac{1}{\sqrt{n} ln(x)} (3)\sum^{\infty}_{n=1} \frac{(ln(n))^{2}}{n^{\frac{3}{2}}} Homework Equations...

Test question: "Water has pH of 7. Which solution has a [H+] concen.." 1. 2. First of all, increasing [H+] concentration will give something more acidic. Since every jump between pH numbers is a 10 fold difference, I thought that to make a 100 fold difference, you would have to do...

Test question: "Respiring cells release CO2 into the bloodstream..." 1. 2. For this question, I was thinking about the nature of CO2. It's not an acid or base, so how could it drop or raise the pH level?! So I put that the pH level won't change (B), but the real answer is C (it will...

Test question: "How many carbohydrates in this food were contributed?" =_= I think my other posts were deleted. So let me post them again with some revisions... 1. 2. Alright... I thought that maybe the percent daily value had something to do with calculating the answer. So on the test...

I am given 4 potential charges, 1V, 3V, -6V, and 5V, all arranged randomly around each other. There is a test charge located at infinity. No distances are given between the potentials.1. Where will a test charge of 2*10^-6 C travel? 2. What is its kinetic energy? 3. Find the capatinance of a...

Hello, Hello, I have recorded some discrete data with an unspecified distribution. I have generated some discrete data from a model. I'm looking to check to see if the generated data has the same distribution as the real data. If the data was continious, I would use a Q-Q plot and a...

I'm going to be reviewing some insulated sheets for lining walls. I want to set up an experiment to rank different types of sheet by their level of insulation. I intend to use a digital thermometer with a probe (for example...

I had a midterm Friday I bombed. I never do that. I ended up dropping the class. I've felt horrible since then. I always get As. It was bad because I really liked the class. It was challenging, fun, interesting. Probably my favorite class of the quarter (advanced number theory). However, he...

Okay I'm currently doing a thrust block design for a water supply system. The new line is a 250mm line. The water is fed from water towers where council has said the operating head is about 30m. I've set up my thrust block program in excel and it is all working fine. The only trouble is I'm...

Homework Statement A rod of negligible mass is supported by a hinge at the wall by a horizontal wire fastened at a 30 degree angle one-third of the way along the rod. A weight of 12 N hangs from the left end of the rod. a) Find the tension (T) in the horizontal wire. (T = 62.2 N) b) Find...

Hi What do you think is the best way to test an Arduino sketch without uploading to the board? ie. What is the best piece of software available? I’m currently writing an Arduino sketch and it would be very usefull if I could test it without having to upload it to the actual Arduino board...

http://download.cnet.com/8301-2007_4-57564385-12/microsoft-bombs-another-security-test/?tag=nl.e415&s_cid=e415 Above from CNET.

Homework Statement Your task is to determine: a.the length and bore of cannon that is required to accommodate an 80 kg Clown with an over-arm measurement of 48 inches b.the amount of fuel that is required to launch the Clown at the same angle as you did with your model...

The thought experiment starts with the basic experiment shown here: http://en.wikipedia.org/wiki/Relativity_of_simultaneity "A flash of light is given off at the center of the traincar just as the two observers pass each other. The observer on board the train sees the front and back of the...

Hi, I'm trying to do a two-sample Kuiper test on aspect data in R but am having no joy as there doesn't seem to be an inbuilt function. Does anyone have any ideas how this can be done? Thanks

Show that the sum of (n/(3n+1))n from n=1 to ∞ converges. The book solves this with a comparison test to (1/3)n, but I'm making a mistake with an n-th term test somewhere. an = (n/(3n+1))n Take ln of both sides, then use n = 1/(1/n) to setup for l'Hopital's rule. ln an = ln(n/(3n+1)) /...

So I'm thinking that after I get my B.Sc in physics from an American university, I will do my Master's degree in the UK (or maybe Australia), I heard they don't require GRE? Is it easier to get admitted there?

Hello, My name is Ryan and I'm a volunteer instructor with the local Royal Canadian Air Cadet squadron. I'm looking for ways to try and make the kids' aviation lessons more interactive and hands on, and so I've decided I'd like to build them a small wind tunnel, purely for flow visualization...

Hi guys I'm trying to find out the nature of this serie \sum_{n=1}^{\infty}\left[ e^{1/n}-e^{-1/n}\right] I know the ratio and root tests are inconclusive, just the comparision test works (it diverges) But with which expression shall I compare? Thank you so much

It states it should take ten minutes to complete. Try it out. I scored 0% http://www.open.edu/openlearn/body-mind/psychology/take-the-photographic-memory-test

Homework Statement I have access to a test facility for window type air conditioners that has a small room that is used to simulate the outdoors. I need to use the facility to test the effect of temperature on the performance of one of our window type AC units. The performance must e done as a...

Hey guys, I did most of the IQ tests on the internet and I get about 140 in most of them but I couldn't do this one http://www.matrix67.com/iqtest/ I coun't even do question 1 so I am really curious to know how to do them :(

I have been wondering: Given an arbitrary geometric shape is there a sequence of tests I can perform on individual parts of the shape to determine whether or not it is achiral? I was hoping for something a little less trivial that simply seeing if the mirror image could be adjusted to...

Homework Statement Question: "What does a polygraph test measure; skin resistance or conductance?" To me this is two sides of the same coin and it seems it must be measuring both. Homework Equations The Attempt at a Solution I thought that the person is acting as a resistor so I wrote down...

Holland strong inventory test and the Myers Brigg Personality test. Has anyone on this forum taken these career assessment tests? Thoughts and opinions? Are there any professional career counsellors on this forum and, if so, what do you think of these tests?

Homework Statement Determine if the following integrals are convergent or divergent. Explain why. \int^{1}_{0} \frac{1}{1-x^{4}} dx The Attempt at a Solution I've tried using Comparison Test, using f(x) = \frac{1}{1-x^{4}} and\; g(x) = \frac{1}{1-x}, 0 \leq f(x)\leq g(x) in ] 0,1 [ and I...

Hello! I have a question from a test that I wasn't sure about, so I guessed. The question is: f(3)= 5 g(3)= -4 f'(3)= 1.1 g'(3)= .7 What is fg'(3) Answer choices: a) .9 b) .4 c) -.9 d) -.4 Does anyone know the answer? And how did you get it? Help would be much appreciated. Thanks!

Block 1 moves with speed of 10m/s to right. It hits block 2 which has twice the mass of block 1 and speed of 5m/s to right. compute the magnitude and direction of block 1 for a perfectly elastic collision. solution: u1 = 10m/s u2 = 5m/s m1v1 + m2v2 = m1u1 + m2u2 ----> v1 + 2v2 = u1 + 2u2 ...

Homework Statement 13 equal charges are placed at the corners of a regular 13 sided polygon. What is the force on a test charge at the center? Homework Equations Coulomb's law Principle of Superposition The Attempt at a Solution Coulomb's law gives an answer of 0, but it is...

Hello. We got an assignment of 105 math problems. I solved them all except the ones I wrote on a sheet of paper and took a picture. If anyone can help me with ANY ONE OF THESE, I'll be very grateful. This is a study review and I need to have the solutions so I can study for my tomorrow's test...

So the laser test with the slits is as followed as far as I understand. When observed, electrons act as particles. When not observed, electrons act as waves. How can electrons know if your eyes are open or closed? Unless your eyes give off some wort of radiation that it can pick up on...

According to GR, the inertia of bodies is greater near masses. - https://en.wikisource.org/wiki/Geometry_and_Experience Has this been tested? I did not find a clear answer, the gravity tests seem to be testing other things. Can it be tested? Intuitively I think that it should be possible...

I recently purchased two strings of RGB LED lights, the kind you can set to all sorts of colors by combining red, green and blue in various amounts. Unfortunately, I strongly suspect that the blue and green led-pieces produce light that is contaminated with UV. Various UV-reactive things in...

I have a time series of climate data that I'm testing for stationarity. Based on previous research, I expect the model underlying the data to have an intercept term, a positive linear time trend, and some normally distributed error term. In other words, I expect the underlying model to look...

Here goes try number two, the forum deleted my last post. :cry: First time poster, so hopefully I'm following the rules, I do apologise if I'm not. I have a problem with my lab report, I would be very grateful if anyone could help. Thanks. Homework Statement I'm writing a tensile test lab...

Homework Statement When calculating the P-value, must you change the sign of the test statistic depending on the type of test (lower, upper)? For example, if your calculated test statistic is t=2.5 and you want to perform a lower-tailed test, is your answer the cumulative probability of...