normal distribution

  1. B

    programme evaluation: normal approximation to binomial

    Housing first is an approach to reducing homelessness. Supposedly, it has 80 percent success rate, which means that on average 80 percent of programme participants tend to retain their housing, and not fall back to homelessness. It is also said that to reliably evaluate the effectiveness of...
  2. D

    Choosing prior for the regression coefficients in the logistic regression

    I'm trying to model Bayesian logistic regression model (using JAGS in R) with my dependent variable (status: 0=alive, 1 death) & independent variable (age) in the categorical form (0=patients < 65 yrs old, 1=patients >=65 yrs old). I'm using normal dist. as a prior for constant term, b0 and...
  3. S

    Does frequency distribution matter when using nominal/ordinal data?

    I want to do relationship analysis between different variables from questionnaire results that I've just collected and I've recently learned that you need to make sure certain assumptions are fulfilled before using certain analysis tools such as needing to have a normal distribution for your...
  4. F

    Exercise on standard distribution

    Hello, Suppose I want to calculate the probability for a user to pass from a basic to a premium account within the end of Q1 (i.e. end of march). I know that this is distributed with mean=50 days and st.dev=10 days, then the probability that a user pass to a premium account within the end of...
  5. C

    Doing Parametric Tests without normal distribution

    Hello everyone! Is it true that when your sample is more than 30 people, you can do parametric tests, even though your sample may not follow the normal distribution? In my research I have 400 people as a sample, not following normal distribution and someone told me that I can do parametric...
  6. M

    Help with normal distribution

    Hello friends of the forum I have the following doubt ... If I have a sample of only 24 discrete data, how can I prove that these data follow a normal distribution? When I enter the data into a specialized software, the software tells me that the sample fits a normal distribution, but I'm...
  7. A

    Which test should I use for two unequal groups ?

    Hi all! I have data that include 20 samples divided into 2 groups (category A and category B). The groups are independent, none of the value in one group repeat in other. N(A) =14, N(B) = 6. here is the data: category A category B 0.0119888167559 0.023185483871...
  8. I

    How to evaluate Mean and Variance of Min Function??

    Detail is Given in Image attach
  9. D

    Racing

    Hi all, I need some help with some statistical work: So, I am trying to understand how I can transform time into probability. I have 2 teams playing a game for 10 minutes. One team scores 1 pt per each minute and the other team takes 1,5 minutes in average to score one point. I want...
  10. T

    Creating standard normal distribution with difference variances within quartiles

    Hi, I have 10,000 data points referring to data on dogs that follow a positively skewed distribution that I have grouped into quartiles. I would a second distribution (highly correlated with the first distribution) associated with the same set of dogs whereby the distribution represents a...
  11. C

    Equivalency testing - CI approach and TOST don't match

    Hey everyone, I'm doing some equivalency testing with both the CI approach and TOST to demostrate the equivalency of two scanning methods. For most of my samples, results align as one would expect, i.e. if the CI lies within the upper and lower bounds, the p-values calculated with two...
  12. T

    parametric or non-parametric in comparison of a dependent variable within several gro

    down vote favorite I am comparing maths and chemistry scores of students in several schools. I am not comparing the schools with each other. I am just trying to say that students do better in maths than in chemistry in all of the schools studied. So I am comparing the maths and chemistry...
  13. Z

    Plotting in r

    Hi There I've goodness of fit my data 2 times. one time for normal distribution and another time for T.distribution. I have about 2500 data and I need to do graphical illustration now. my graphical illustration should be mix of ecdf and cdf for each of them( normal and student t). I'm pretty...
  14. E

    Normal distribution

    Hi all, I'm generating a random normal distribution and i don't control the mu and sigma (its a matlab function that i need to use because the ratio between the numbers). Is there any way to change the mu and sigma and still keep the same ratio between the numbers in the vector? I hope you...
  15. Y

    For the Normal Distribution, why < and <= is the same thing?

    For the Normal Distribution, why is the case that "<" (less than) is the same thing as "<=" (less than or equal to), computationally? That is, why can we summarily disregard the "equality" portion?
  16. J

    Help Building Useful Normal Distribution Calculator

    I want to develop my own Normal Distribution calculator, to provide to a developer to perform a task within an app. I want a user with little knowledge of statistics to be able to perform, and understand Normal Distribution calculations. Here is what I want it to accomplish . . . Given the...
  17. A

    Normal Distribution

    Suppose that in an apartment building run by the Probandstat rental company, the inhabitants's weights follow a normal distribution with mean 73.0 kilos and standard deviation 13.65 kilos. A new elevator must be installed. The elevator company rates the safe carrying capacity of the new...
  18. N

    stuck with this problem!!!! need help

    The minimum force required to break a particular type of cable is normally distributed with mean 12,432 and standard deviation 25. A random sample of 400 cables of this type is selected. Calculate the probability that at least 349 of the selected cables will not break under a force of 12,400...
  19. M

    Determining outliers

    Dear folks, I am interested in statistics but I never had a course in college and I've had to learn a few basic things myself. This time, I am working on something that is beyond my comprehension. I have a set of environmental data (20 soil samples) which I am playing around with. (See below.)...
  20. D

    Comparing a Binomial and Normal Distribution

    So I'm currently analyzing several sets of data, that all represent the exact same type of data. There are multiple sets of this data, but however are in different forms. That is, some of this data is in the binary form, either presence of absence, while others are in the quantitative form. My...