Ongfufu Posted March 18, 2009 Report Share Posted March 18, 2009 there should be 12....and i don't think we can calculate expected frequencies for poisson distribution b'causeit is only applicable for discrete random variable.............and that software is 'graphmatica' and not 'graphatica'.....We can't calculate expected frequency for poisson? Isn't that what the question asks? Reply Link to post Share on other sites More sharing options...
catx Posted March 18, 2009 Report Share Posted March 18, 2009 People who have a Mac, a good idea is to graph with Grapher 2.0. It can also help you to find the expected frequencies for normal distribution. I'm quite stuck with question 5 and 6. Can you give me a clue on them, please. Also the Poisson part is quite weird, I really have no idea on how to pull out the frequencies. The thing is that Poisson is discrete and it can hardly be applied to the values we have been provided with. As mentioned fractions can't be factorized.Thanks for the help(in advance). Hope we manage to pull it off eventually. Cheers Reply Link to post Share on other sites More sharing options...
Munesh Yagna Posted March 19, 2009 Report Share Posted March 19, 2009 (edited) well...i haven't found a method to calculate poisson distribution.....but i tried calculating using many methods........the sum of the expected frequencies of poisson shud be 1000....but i ain't gettin that...so it means that my methods are wrong......so i thought....to move on with the next Q.....i think people who r stuck on that Q shud also move on.....if anyone do get an idea to calculate exp. frequency for poisson....then pls help!!!!!! Edited March 19, 2009 by Munesh Yagna Reply Link to post Share on other sites More sharing options...
Mahuta ♥ Posted March 19, 2009 Report Share Posted March 19, 2009 Please don't text speak, it's not allowed. Reply Link to post Share on other sites More sharing options...
Ongfufu Posted March 23, 2009 Report Share Posted March 23, 2009 Is there a significance of mean being less than 1 in a Poisson distribution? Reply Link to post Share on other sites More sharing options...
mathpoet Posted March 24, 2009 Report Share Posted March 24, 2009 Is there a significance of mean being less than 1 in a Poisson distribution?You can not do it that way, because you are working in cm.Try 1/4m as unit. Reply Link to post Share on other sites More sharing options...
Ongfufu Posted March 24, 2009 Report Share Posted March 24, 2009 You can not do it that way, because you are working in cm.Try 1/4m as unit.Hey mathpoet, what am I doing wrong here? Is my mean wrong? I'm not sure what you mean. Reply Link to post Share on other sites More sharing options...
mathpoet Posted March 24, 2009 Report Share Posted March 24, 2009 Hey mathpoet, what am I doing wrong here? Is my mean wrong? I'm not sure what you mean. The thing is: the Poisson can work only with integers so you have to find a way to turn the data into integers. So cm are not a good solution. Multiplication by 4 could solve everything, and then you're actually using a unit of 1/4m. Reply Link to post Share on other sites More sharing options...
Ongfufu Posted March 25, 2009 Report Share Posted March 25, 2009 The thing is: the Poisson can work only with integers so you have to find a way to turn the data into integers. So cm are not a good solution. Multiplication by 4 could solve everything, and then you're actually using a unit of 1/4m.Ok I've realized that too. But I just indexed X from being "height" into "interval number", so that X=0,1,2,3... I've calculated expected frequencies for Poisson with X being integers, and the sum ends up being 1. It seems promising since it adds up to 1, but some of my friends say I can't change X into integers, and suggested what you said. I'm pretty confused. Even though it adds up to 1, I know it doesn't fit the sample because of the shape of the curve. Reply Link to post Share on other sites More sharing options...
mathpoet Posted March 25, 2009 Report Share Posted March 25, 2009 Even though it adds up to 1, I know it doesn't fit the sample because of the shape of the curve.You need cdf of data, not pdf. And mean should also be in 1/4m. Reply Link to post Share on other sites More sharing options...
Ongfufu Posted March 25, 2009 Report Share Posted March 25, 2009 You need cdf of data, not pdf. And mean should also be in 1/4m.Poisson is only needed in question 2, which doesn't require a cdf. Reply Link to post Share on other sites More sharing options...
khp1991 Posted June 13, 2009 Report Share Posted June 13, 2009 If values are taken to a 1/4m, this doesnt make the Mid interval value an interger.Isn't that the value we are actually supoosed to use when doing Poisson cdf on the calculator? Reply Link to post Share on other sites More sharing options...
msk Posted August 6, 2009 Report Share Posted August 6, 2009 Can anyone one help? im kinda stuck on #2. for poisson i converted the heights to centimeters and im using 88.625 for the mean. these are the first few numbers that i got. 1.4134E-12, 0.005664067, 78.86415618.i have no idea what to do for the normal distribution column. Reply Link to post Share on other sites More sharing options...
kool_kid296 Posted November 29, 2009 Report Share Posted November 29, 2009 I did the exact same thing. I dont no what to do. Reply Link to post Share on other sites More sharing options...
kool_kid296 Posted November 29, 2009 Report Share Posted November 29, 2009 I cannot figure out how to do the poisson distribution for the data. can anyone help me? if it helps for me to write out the problem i can do that just let me know. Reply Link to post Share on other sites More sharing options...
Austin Glau Posted December 2, 2009 Report Share Posted December 2, 2009 Your answer, 0.001870472, is the probability that the expected/predicted number of occurrences in the interval {1.00-1.25}will be 0.88625 when there are 5 occurrences.I would think that you would use 158 somewhere in there because it is the exact number of occurrences when the saplings were from 1.00 to 1.25m.But because I do not know the full extent or purpose of the portfolio, i cannot say that it should be included. It depends on the portfolio. Reply Link to post Share on other sites More sharing options...
kman Posted March 17, 2010 Report Share Posted March 17, 2010 hey everyoneim stuck on number 5. what exactly is a cumulative RELATIVE frequency curve, and how on earth is that supposed to help us find a pdf. Also, is the general goal of the assignment to find a function that models the data? If so, why can't we just plot the midclass values and frequencies on excel and generate a line of best fit and an equation ? Reply Link to post Share on other sites More sharing options...
hero of IB Posted April 2, 2010 Report Share Posted April 2, 2010 (edited) Anyone done with this assignment? I got to the forth question and I stuck. Any help please!!! Edited April 2, 2010 by hero of IB Reply Link to post Share on other sites More sharing options...
cotezen Posted June 25, 2010 Report Share Posted June 25, 2010 HiI am half way through the assignment and stuck on question 6...I don't understand. I have the cumulative relative frequency curve, am I supposed to find a function that best fits onto it, or do I find a distribution whose integral is almost the same as my frequency curve? Am i looking for a function or a distribution? We have only studied 3 distributions, poisson, normal and binomial and I know for a fact that neither of those will be the correct ones...which explains why I am stuck. Could someone please point me in the right direction?cheers,Jason Reply Link to post Share on other sites More sharing options...
Pocillovy Posted August 11, 2010 Report Share Posted August 11, 2010 Hi! I'm on number 7, can somebody help with it? Reply Link to post Share on other sites More sharing options...
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