normal curve

  1. M

    What is normal curve actually?

    Hi All, I am fairly new to Stats and thus this question. I was going through different materials to learn stats. 1. Somwhere its mentiond that a population, if plotted against frequency on a bar graph can produce a normal curve (e.g popcorn popping, heights of people etc) 2. Whereas somewhere...
  2. M

    Unimodal Link-function possible?

    Hi, using a GLM model (e.g. a Poisson regression), there are various link functions available in statistical packages. However, I don't find an unimodal depedency ("Normal/Gaussian link"), and I always have to approximate an unimodal relationship with polynomial terms. Does somebody know why...
  3. B

    Normal Curve & Standard deviation HELP!

    This is my homework question and in my right brained mind can not or the life of me think any further. My only hope is that someone out there in the universe can help my melted brain: Pick a continuous variable (that is, interval or ratio in scale of measurement) that is normally distributed...
  4. E

    Why are these statements false?

    Hello, I was doing a practice test and I got two questions wrong. The answer key said that these two statements were false: As sample size increases, the standard deviation of the sampling distribution and the standard deviation of the population are increasingly similar. -and- For the...
  5. J

    Odd Z table value

    Hey everyone, I'm trying to make sense of a Z value I wrote down in class. I understand how the Z table works now, but before I got there I made a note in class about a certain Z value and looking through the table I can't make sense of the note now. Perhaps I wrote it down wrong. Any...
  6. F

    Plotting a normal distribution curve over a histogram

    I'm trying to plot a normal distribution curve over my histogram but I can't get my code to work for the curve. It just looks like it's plotting a very low curve, what am I doing wrong? This is my code: minutes<-c(107, 116, 127, 126, 111, 90, 125, 124, 92, 121, 131, 137, 95, 101, 101, 111...
  7. D

    Mean and Median for testing data distribution

    Hi, I noticed that in the following articles data distribution is tested via checking for >10% difference in mean and median. http://www.sciencedirect.com/science/article/pii/0022175996000130 http://www.sciencedirect.com/science/article/pii/002217599500078O However, when I follow the...
  8. R

    find area under non-standard normal curve (i.e. units not percentages)

    Hello, I would like some advice on how to calculate the area under a non-standard normal curve, in its own units, not relative to a standard-normal curve. Example distribution characteristics: Mean :500 Standard Deviation: 100 Point of interest: 550 By finding the relevant Z-score...
  9. C

    product of N normal distributions

    We are given N normal functions, with means \mu_i, and variances \sigma_i^2, i in 1...N. I need to find a formula for the product of the N functions. The case N=2 is easy to find online: https://ccrma.stanford.edu/~jos/sasp/Product_Two_Gaussian_PDFs.html but I have found nothing regarding...
  10. D

    Transforming Truncated Data - Possible? Suggested?

    I have now spent countless hours/days looking in statistics texts and performing online searches to determine the appropriate way to treat my current data scenario. And, I have found no answers.:confused: I am using "high school GPA" data as collected by a university as an independent variable...