correlation

  1. K

    University project help (correlation)

    Hello dear stat-folk! I'm currently in the process of re-writing my project due to a failed exam in it. In this regard i'm having trouble figuring out whether i can even use statistics (and how) to describe a theory i have towards a possible correlation. In this part of the project i am...
  2. P

    Advice on which analysis to use for count data...

    I am looking to examine whether one variable (counts of social interactions) is associated with another variable (counts of running activity). Both variables are simply frequency counts of behaviours which were counted at the same time during 40 hour-long observation periods across two weeks...
  3. M

    Comparing correlation coefficients

    Hello, I have a large sample of patients who have had a TIA, minor stroke or major stroke. I have been looking at correlations in each of these three groups. Is there a statistical test in SPSS (or elsewhere) that would allow me to compare the correlation coefficients between each of three...
  4. W

    panel data correlation

    Dear All I want to study the effect on ROA for a pharmacy that has an online pharmacy department compared to pharmacies that don't. This is my regression: Return on assets = b0 + b1*ln(total assets) + b2*ln(firmage) + b3*leverage + b4*current ratio + b5*dummy online pharmacy + b6*dummy online...
  5. S

    Can a ratio of performance be used to measure dependence and assign weights in a weighted average?

    With only a modest grasp of inferential stats and maths in general, I've been wondering how one might derive the weights for a weighted average from a variable that isn't as straightforward as a frequency score. Consider the following scenario. Let's say I have measurements of effectiveness for...
  6. A

    Test for Multicollinearity

    Hello Talk Stats Forum! I am working on building a Predictive Model using the binary logistic regression and LASSO logistic regression. In order to apply these models on some real data set I am using R software. Before performing such a model I am testing for multicollinearity and will remove...
  7. D

    correlation

    Hello. I have 99 patients divided into subgroups according to the following variables: 1- Their syntax score (which measures how severe the obstruction in coronary arteries is). Values of this variable are between 10.2 and 41 and are classified into three levels, first 1-22, second 23 - 32...
  8. T

    Correlation analysis: spearman or pearson

    Hi, We are conducting research on the relationship between self esteem and aggression. We have aggression scores and self esteem scores and we want to find out if there is a significant difference in the relationship by gender. We have ran a pearson's correlation for the relationship for the...
  9. T

    Multi-correlations analysis

    Hi everyone, I’m recently struggling with a situation below, may anyone be kind enough to offer me a helping hand please. Student / mins of leisure time / page studided / marks in exam A / 50 / 100 / 90 B / 55 / 85 / 80 C / 60 / 80 / 70 Now for student D, he has 50 mins leisure time and...
  10. M

    Agreement between 2 measurement methods

    Hi, I am trying to find the agreement between 2 methods that estimate the size of a knee (CT and MRI). n brief, each knee can get a size from 1-7 where 1 represents the smallest size available and 7 represents the biggest size available. In my study, I have 100 different knees that were...
  11. C

    Correlation of two variables through others

    Hi, I have two data sets. In both sets there are 3 of the same variables (density, MOE and frequency). In addition to that, each set has one more variable (tension strength and bending strength). Since i can not measure both strengths on one piece, I would like to estimate the correlation (or...
  12. M

    Relationship between a variable with categories and a variable with numbers?

    In SPSS, is there a way to find out if there is a siginificant relationship between symptoms (on a scale from 0-3, with 3 = the worst) and hospital stay ("yes" or "no") are related?
  13. M

    Can I use chi-square for one nominal and one ordinal variable?

    Can I use chi-square test of independence if one variable is nominal and the other is ordinal, or do both have to be nominal?
  14. H

    Correlation Coefficient.

    1) If the correlation coefficient between two random variables X and Y is 0.5, then the correlation coefficient between 2X-4 and 3-2Y is? a. 1 b. 0.5 c. -0.5 d. 0 1) If the correlation coefficient between two random variables X and Y is 0.3, then the correlation coefficient between (2X+3)/5...
  15. H

    Coefficient of correlation.

    1) If the correlation coefficient between two random variables X and Y is 0.5, then the correlation coefficient between 2X-4 and 3-2Y is? a. 1 b. 0.5 c. -0.5 d. 0 1) If the correlation coefficient between two random variables X and Y is 0.3, then the correlation coefficient between (2X+3)/5...
  16. H

    Is this an interval variable?

    The variable is called "externalizing behaviours" and it has the numbers 9,7,7,3,11,6,2,6,6,9. I assume that the numbers show the amount of externalizing behaviour because the question says it was an observation. Is this interval/ratio? I think it is interval (rather than ordinal) because 7 is...
  17. S

    Generating data from exponential distribution in r.

    Suppose X~exp(.67), Y~exp(.8), Z~exp(.43). X and Y are correlated with a correlation coefficient of -0.6. Again X and Z are correlated with a correlation coefficient of -0.6. How can I generate data from X, Y and Z by incorporating this correlation. I know if they were uncorrelated, I could...
  18. P

    is multiple regression the right choice for me?

    I am trying to ascertain the relationship between three variables; two independent and one dependent so I'm fairly confident that a multiple regression would be the correct choice. However I'm not sure if this is correct because of the fact that I have repeated measures. I have repeated...
  19. E

    Zero order correlation negative, Direct effect Positive

    Hi, I am performing mediation analysis, and have first of all looked at the correlation between variables. The zero order correlation between X and Y is positive and significant. However in the mediation analysis, the direct effect of X on Y (after holding the mediator constant) has a...
  20. S

    Correlation in questionnaire data

    Hello, I'd really appreciate if someone can help me with a particular problem, concerning the approach I should take in statistically analysing the results of questionnaire data concerning intensity of use of social media, on the one hand, and social relationships on the other. The...