My Math Forum Chi Square Sample Size

 March 21st, 2012, 01:28 AM #1 Member   Joined: Nov 2009 Posts: 90 Thanks: 0 Chi Square Sample Size Hello, I want to do a test of distribution. That is, I want to find out what the statistical distribution is of a certain variable. Let's say it's the weight of apples, since I like fruit analogies. Let's say I want to know if the weight of apples are normally distributed (or log-normal or whatever). So I weigh n apples and enter the data into a list and divide the weights into c classes and count the amount of apples that belong to each class. From what I've read, the only requirement on the sample size n, in the chi^2-test, is that the expected frequency of any one class must be at least five. But this seems like an insufficient measurement of reliability, doesn't it? Weighing 15 apples and dividing it into 3 classes can't possibly be equally good to weighing 1500 apples and dividing it into 300 classes. It appears to me that I would trust the result in the latter case more than in the first case. It seems plausible to believe that the variance of the resulting p-value should be inversely correlated to n and c. But this is just a hunch I'm having and I can't prove it. So I'm asking you, how many apples do I need to weigh? Thank you!

 Tags chi, sample, size, square

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Engr Faisal hbaib Advanced Statistics 0 November 23rd, 2013 06:25 PM Jessicasamide Advanced Statistics 1 November 20th, 2012 11:21 AM jskrzy Algebra 1 November 16th, 2011 04:17 PM waza086 Algebra 0 March 21st, 2010 02:54 AM symmetry Advanced Statistics 0 March 30th, 2007 04:09 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top