correlation

  1. H

    Choosing appropriate statistics (please)

    Hi, I have an issue (mostly being clueless and trying to achieve more than I can), I am writing a page in Ruby on Rails for which I need to calculate the probability of two events being correlated (basically the likelihood of a trigger being the cause of a symptom, or since correlation doesn't...
  2. D

    Generating confidence intervals for both height and weight with the same sample?

    Given that height and weight tend to be correlated, would it be okay for me to use a single simple random sample of people to create confidence intervals for both their height and their weight?
  3. D

    Data set simulation

    Answered on other threads, sorry for posting
  4. R

    Interpreting correlation split file data

    Hello, I ran a split file correlation with the race as a group. I am not sure how to interpret a section of this chart, particularly the last section which is labeled "9.00." Is that a summary? What does that mean? Thank you,
  5. N

    Permutation correlation with one non-normal variable

    Hi, I am trying to assess the relationship between a relatively normally distributed variable (brain volume) and a strongly right-skewed behavioral measures, which cannot be transformed to normality. I assume a linear relationship between the two variables. My plan is to calculate the...
  6. V

    Joint Density Function From Given Correlation

    How do I find joint density function from a given correlation?
  7. R

    Power Analysis

    Hi there, I am currently writing a statistics report which has to cover 2 questions: Firstly, what the correlation is between two different test scores of 30 participants. Secondly, what the power of the study is. I am really struggling to grasp what the pro's of doing a post-hoc power...
  8. H

    nominal (yes/no) and distance. What test to use to proof correlation?

    Hi all, My boss has a list that shows the interest of people for a new venue (interest? Answer: yes or no) and the distance to that possible venue. He asked me to show if there is any correlation between the two of them.. Although I searched and searched, I find it hard to decide which test...
  9. S

    Question on the merits of mediation analysis Vs another analysis (described within)

    Hello, I have a dataset involving an intervention (placebo versus real) - denoted as X, an outcome (Y), and a physiological variable (M) that I hypothesised would mediate the effect of X on Y. I have shown that X did not significantly affect Y (as assessed using simple linear regression), but...
  10. J

    Find Correlations

    Let's say I have some samples, that I gathered per second, like these Number km Benzine Speed Weight 1 10 100 80 100 2 20 90 100 120 3 30 80 80 110 with thousand of samples and more than twenty features (like speed and...
  11. K

    Multivariate correlation coefficient?

    Is there a simple definition (formula) for a multivariate correlation coefficient between k binomial variables, assuming that each variable is positive with the same probability/frequency f? What does the CDF for this multivariate binomial distribution look like, and how does it depend on the...
  12. S

    Correlation based on multiple measures / observations

    Hello everyone! I am hoping someone could offer me some wisdom and a few R tricks. I was lucky enough to get a pretty interesting data set for a study that I am doing. There is approximately 5000+ rows of data spanning 5 years for 100 different sales people. The data is structured per...
  13. K

    Correlation betweeen k binomial variables

    Hello, This is my first post as a new member, so hope I'm posting this in the right place... I need a general formula to calculate the minimum sample size N required to determine whether k binomial variables are somehow correlated (either positively or negatively) at significance level p<=...
  14. F

    Created a function that works fine but when asked to operate on its output it fails

    Hello, I have an assignment that requires me to create a function that calculates the correlations between two columns of 332 csv files based on my input. In short, what it does is find correlations between two columns of only the files that have either the same or more of complete cases as...
  15. S

    What method for this problem? [Correlation / Correspondence]

    Hi, I have a data set like the following with some categorical/nominal values (like Gender and Age Group) and a ratio scaled value (DropOut, which is the week after registration in which a person dropped out of a program [so it's never zero or less, and it's not the calender week]): I want...
  16. G

    What is best method to calculate correlation for 2 nominal variables?

    Hello, I am analyzing data that looks at several nominal variables (e.g. employment status, race, gender, etc.) to determine if it plays a factor in the person's adherence to medication (also a nominal variable). What is the best way to do that? From what I've read on the forums and...
  17. E

    Need Help with Correlation

    Hi, I am trying to figure out the best way to calculate correlation with data I have for my business. Here is an example of what I the fields: Sale Amt - numeric Sold - yes or no State - lists 1 of 50 states Industry - lists the industry of the buyer Lead Source - lists where the lead...
  18. B

    WTI price vs. Drilling Cost Index

    Hi Folks, I have 2 datasets, each recorded on a monthly basis. The first dataset is the average monthly oil price. The second is a price index for drilling cost. I was to calculate what % change in drilling cost to expect with a 1% change in oil price. The data set spans 8 years and you see a...
  19. A

    Unsure what SPSS test to run--comparing means.

    I am a SPSS beginner. My hypothesis is "Women who score high on self-esteem will score low on upward comparison than women who score high on upward comparison." I have all the data cleaned up and the total scores found for all my scales, I am just unsure what SPSS analysis I should run. Is it...
  20. B

    Why one-tailed sig. in SPSS Regression Correlation

    Given that a two-tailed significance test is usually preferred unless one has a hypothesis about the direction of the relationship, why in the Regression descriptives output does SPSS default to a one-tailed test for the correlations, without any way I can find to change it to two-tailed?