answers to textbook Understanding basic statistics?
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You can buy one (if it's still in print) at your local bookstore.  Or perhaps order one from an online retailer or search amazon.com
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If the population has a mean of 58 and a sd of 8, then the sample means of size 100 will have a mean of 58 and a sd of 8/sqrt(100) = 0.8\n\na) Within 3 of 58 means that the sample mean will be between 58-3 = 55 and 58+3 = 61\n\nz = (55-58)/0.8 = -3.75\nz = (61-58)/0.8 = 3.75\n\nFrom the table, the area between the two is almost 1.\n\nb) The mean weight is less than 2.5 of 58 or more means less than 58-2.5 = 55.5\n\nz = (55.5-58)/0.8 = -3.13\n\nFrom the table, the are greater than that is almost 0.\n\nc) z = (57.5-58)/0.8 = -0.63\nz = (58.7-58)/0.8 = 0.88\n\nFrom the table, the area between is 0.811 - 0.264 = 0.547.\n\nd) 56 +- (1.96)(0.8)\n56 +- 1.568\n(54.432,57.568)
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sounds like there are a few answers... maybe your text book will help?
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n = N/(1+Ne(e))\n\nWhere:\nn = number of samples\nN = total population\ne = margin of error\n\nI could not find the squared key on my board so i just manipulated it, however it is the same.
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Please visit the following web sites :\nhttp://www.people.ku.edu/~gbohling/cpe940/Variograms.pdf \nhttp://www.www.springer.com/west/home/geosciences/ geo+textbooks\nhttp://www.pedometrics.org/on_pedometrics.asp \nhttp://www.ecostat.info/geostats/prac-geos.html \n....These should give you an idea of what textbooks would best suit your needs !
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I've found that the Wikipedia articles on probability distributions are top notch and contain enough information for you to solve this problem on your own.\n\nHint: solve the algebraic expressions that relate mean and variance so you can express p or n as algebraic relationship of one another and then do some substitions.\n\nAt first I thought you needed to know p or n up-front however I realize that you have all the info you need to solve this problem algebraically.\n\nGood luck with your homework.
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What you're looking for is the standard deviation.  If the data values are X and the mean is XBAR, then\n\nS.D. = sqrt{[SUM(X - XBAR)^2] / n}\n\nn is the number of data items, and SUM means to add up the squares of the differences between the data values and the mean.\n\nThe lower the standard deviation, the more tightly packed the data.  If the data is normally distributed, about 68% of the data will lie within one standard deviation of the mean, and 95% will be within two standard deviations.\n\n[Edit:  In light of the previous answers, I should add that the standard deviation is the square root of the variance.]
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Quantitative methodologies... statistical analysis?   How many pages allowed on here... there are books and books about it... try reading literature on the above... infinite (well almost!) sources available on line, at the library and in book shops
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See p. 541 of Econometric Foundations by Mittelhammer, Judge and Miller.  Will be a bit tough to explain on Yahoo.  Actually, I don't like this book, but none of my other ones have this.
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You can expect mind numblingly boring calculations for most of your summer.  The mathematics behind statistics is fairly elementary, it's the staying awake and alert part that's difficult...\nGood Luck, I had to take Statistics in college, and I have to say... It was the best one hour nap 3 times a week a person could possibly ask for...
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I don't know of any people who tutor online.\n\nThere are a number of good free statistics textbooks.  See the link.\n\nYou may also find it helpful to visit the library and read what different textbooks have to say about things that are stumping you.
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You might try DAP. You can find it here along with a lot of other free statistical software.\nhttp://members.aol.com/johnp71/javasta2.html
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The following link has a number of Yahoo Groups on the topic of math and statistics:\nhttp://groups.yahoo.com/search?query=math.html&submit=Search\n\nThe following Yahoo search for statistics societies has a number of associations included in the results:\nhttp://search.yahoo.com/search?ei=utf-8&fr=slv1-&p=statistics%20societies\n\nAnother Yahoo search for Bayesian Statistics Society lists some other resources:\nhttp://search.yahoo.com/search?ei=utf-8&fr=slv1-&p=bayesian%20statistics%20society.\n\nA couple of specific groups or forums of interest may be:\nhttp://www.mathforum.org/\nhttp://www.bayesian.org/\nhttp://www.rss.org.uk/\n\nIf there is a local college or university, you might contact their statistics department to see if they have such a group or club.\n\nBTW, I quite like Statistics and, 20 years after graduating from university, I'm teaching myself statistics and just finished taking a class in Bayesian statistics. I'm not in the "looney bin". I've used Statistics almost every day for the past 4 years. And the best part -- I'm getting paid pretty well to do it. :^)\n\nGood luck to you!
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As you can see the answers are all over the place.  I have provided a link to a website which shows statistics on a graph from the year 2001.  Although it's not the most current of information, it is a good starting point.
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OK.  From any given population, you can take many, many different samples of size n.  For each of those samples, you can find the mean.  So if you take 1000 samples of size 50,  Then you would have 1000 sample means.  Now each of those sample means are probably going to be different from the overall population mean, since samples are going to look different from the population.  Also, each of the 1000 sample means are going to look different from each other because the mean is coming from different samples.\n\nSo if I were to draw a histogram (hopefully you know what that is; it is a bar graph that you can use to look at the distribution of numerical data).  Anyway, if I were to draw a histogram of my 1000 sample means,  You should notice the following three things...\n\n1.  The center of your histogram should be the same as you population mean (so if the mean of the population is 20, then the histogram of my 1000 sample means should center around 20).\n\n2.  As the sample size gets larger, the spread of the histogram should get smaller (so the spread of the means of samples of size 50 would be smaller than for the means of samples of size 25).  This is because with larger samples, you would have more information about the population, and thus you should be able to get closer to the population mean.\n\n3.  As the sample size gets larger, the shape of the histogram will look more and more like a normal curve.\n\nThis is because of the Central Limit Theorem, that states that if you take a sample of size n from any population with a finite variance, the distribution of the mean of the sample would get closer and closer to a normal curve as n gets larger.  The mean of the normal would be the same as the population mean, and the standard deviation of the normal (usually called the standard error) would  be the standard deviation of the population divided by the square root of n.  Notice that as n gets larger, the standard error gets smaller, just as described before.  So typically you can approximate these histrgrams with a normal curve if n > 25.\n\nThis phenomenon is hard to describe in words alone.  Looking at pictures of these histograms that I described would help you understand it better.
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1. Jessica M Utts and Robert F Heckard (2006) Statistical Ideas and Methods, Thomson Brookes/Cole \n*** (3 stars)\n2. Gerald Keller and Brian Warrack, Statistics for Management and Economics –6th Edition, Duxbury. This textbook comes with a CD-ROM comprising applets for interactive examples, a student study guide and data files.\n****(4 stars) - quite good
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Are you looking for the formula of finding the range of group data.\n\nActually, i have read two methods. \nsome books just get the difference of the highest upper limit and the lowest lower limit of the distribution.\n\nbut some get the difference of the highest upper limit and the lowest lower limit of the distribution plus one.\nThat is, it is the difference between the highest upper boundary and the lowest lower boundary.