Chi Definition and 73 Threads

I have a set of data that consists of about ~1000 data points, each of which has two measurements. I have a series of models with two parameters that I have fit to this data to find the best fitting pair of parameters. There is quite a spread around the best-fitting model, because none of the...

Hi there, I have very naive to statistics. I have a set of data points. that can be like 10, 12, 13, 14 ,15 , 15, 12, 13 17, 18, 19, 12, 19, 20 .... Now i need to know if these days points follows any gaussian distribution / normal distribution or not? IS chi -square test the right...

URGENT help involving Chi squared test! Hello, I am doing a chi squared test for a project due soon and everything is fine, except for one thing...for one of my rows the expected value is zero!...and the equation is (O-E)^2/E...but I can't divide it by zero because that will give infinity...so...

I am confused about the meanings of these two goodness-of-fit descriptors. If I have two independent variables and I wish to test the validity of a proposed functional relation between them (say I have measured electric potentials and currents and wish to test if the data reflects a linear...

What is the Multinomial expansion of the CDF of the Chi-square distribution? Thanks in advance

Homework Statement rvX has f(x) = \alpha \exp^{-\alpha x} , and \ W = 2n \alpha \overline {X} defines a random sample from the distribution. Use moment generating function techniques to show that the distribution of W is chi-square on 2n degrees of freedom. Homework Equations The Attempt...

Homework Statement W = \frac{vS^2}{\sigma^2}, distributed as X^2_v Find E(s^2) and Var(s^2) Homework Equations E(W) = v , Var(w)=2vThe Attempt at a Solution Have been trying to figure this out with no luck. Can I use MLE for variance to show Var(s^2)= \sigma^2? Really don't know how to get...

I am trying to calculate the chi squared function for life data and a confidence level of 95%. I have 10 data points, a specified confidence level (95%), and 1 degree of freedom. I also have the alpha and beta parameters. Based on this information how can i calculate the chi squared statistic? I...

I had this article emailed to me, and I want to see if there are others here who have seen this "speech" to know if it is legit or not. I googled and found the entire article on a website, and I will post the link to the website instead of copying and pasting the entire article as it is long...

Lets say you have 5 trials, and 5 output let's say {5, 43, 60, 30 , 4}...so how would u get the chi sqaure from here & the confidence interval. i haven't work on prob &statc in years, thanks a lot for help folks

Lets say you have 5 trials, and 5 output let's say {5, 43, 60, 30 , 4}...so how would u get the chi sqaure from here & the confidence interval. i haven't work on prob &statc in years, thanks a lot for help folks

Hi all, just a quick query about data analysis: Homework Statement Having been asked to use Chi Squared analysis to test the validity of a fit, I have calculated my data to have a reduced chi squared of ~ 0.75 to 2 dp. I know that a reduced chi squared (chi squared / number of degrees of...

Hi ll, I have been asked to review a new image retrieval technique that has improved the retrieval performance compared with the old technique, ie, the hypothesis is that retrieval performance is influenced by retrieval techniques. The following table summarises the retrieval results. (They...

The following table shows brand preferences against gender on the basis of a random sample of size 100 from population. It is intended to examine possible association between gender and brand preferences. Brand A Brand B Men 30 20 Women 20 30 At 5% level of significance will you...

I'm not sure if this is the right subforum for this thread, but I was wondering what everyone's opinion is on chi energy (AKA qi), specifically the role it supposedly plays in martial arts and medicine. Is there any science to this, or is it just an ancient belief that hasn't completely...

So I have my fit for my data (in this case it's the e/m lab, where the slope of my trend line = e/m). And I calculated the required y - (Ax + B) values, but I have no idea what to use for standard deviation to divide each value by. To be honest, I'm just lost in the notation. I remember in...

My lab partner and I are trying to recreate this experiment: http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1467-9280.2006.01731.x? This appears to be a mixed design. Half the participants were put in a positive mood and half were put into a neutral mood. After the mood induction, each...

In Chinese philosophy they talk of a force called Chi. It's an electrical current that runs through your body,everything around you, and Earth. I'm thinking maybe they weren't wrong. There is an electrical current that runs through you. It's the currents of your nervouce system. his may be...

Hi, My Question: Problem 1. The expected phenotypic ratios for each of the crosses below is 1:1. Determine whether the observed ratios are differ significantly (p < 0.05) from the expected. I used a Chi Square test to help me determine that answer and found the there is no probability of...

Do you really think there is a mythical force called Chi? The Chinese said it was electricity flowing through our bodies down channels called meridians. While electricity does flow through our bodies it's not down meridians but nerves. Do you think that the chinese were really taping into our...

Hi, I am trying to measure fluorescence lifetimes. Typically, the excitation pulse is measured and convoluted with an exponential decay function. This result is compared with the measured fluorescence curve in order to adjust the parameters in the decay function. The process is repeated until...

Hello! While conducting chi square -tests I asked my teacher what the "square" means, and why it was there? Why chi squared, and not just chi? He couldn't give an answer so he told me to find out, as a homework :surprise: ... After a quarter of "Googeling" I gave up. So, is there anyone out...

Chi Meson offline Joined: Aug 2003 Location: Posts: 40 [1.08 /day] Member #: 1431 This might be jumping the topic, but...Other areas: The proof of Bose-Einstein condensate. Old theory, but refined physics? Isn't this "evolution"?... how is bose einstein condensation explained...