correlation

  1. 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...
  2. 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...
  3. 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...
  4. 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...
  5. 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...
  6. 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...
  7. 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...
  8. H

    Is there a Correlation metric for Categorical vs Numerical features?

    I've been searching for some time for a correlation metric analogous to the Pearson correlation value for numerical vs numerical features, or Cramér's V for categorical vs categorical features, but this time for categorical vs numerical features. This is my toy data example in Python, where...
  9. C

    Correlation and reproducibility

    Hi, I just registered to find some answers to probably very simple questions.. I hope those are not answered too often in the forum, but my computer gives me an error when I try to use the search function (maybe due to corporate internet restrictions). Starting situation 1: 4...
  10. N

    What does it mean if my Pearson r correlation is not significant?

    Hi there, So ive got a sample size of 400 Uni students, measuring a correlation between stress and exercise levels in minutes, and I received a non-significant results. Can anybody help explain why this is the case? Im having trouble interpreting it.
  11. V

    Triangulating multiple data sources of prescription information

    I am currently working on a retrospective database study assessing the real-world effectiveness of a medication. I am faced with a few challenges. I have 3 sources of prescription data: pharmacy records, E-Prescribe database, and medication reconciliation information obtained from the nurse's...
  12. B

    Urgent!

    Please please help me! Hello there :) It's probably really straight forward but I'm having a very hard time trying to find a relationship between variables. I have an variable (Self-esteem) and I'm trying to assess whether there is a causal relationship between low self-esteem and if they...
  13. M

    Regression R2-value Vs spearman correlation coefficient

    Greetings I have been assessing some of the relationships between EDTA extractable Pb Vs Pb in plants etc using regression analysis in minitab. I just found a study that did a correlation analysis instead providing the correlation coefficient and p-value in order to assess if the relationship...
  14. D

    Master thesis, statistics check!

    About me: Medical student with minimal statistical knowledge or research experience Question related to: statistical regression/correlation analysis of a medical trial Trial design: Double blind, randomized controlled trial. Placebo vs vitamin with a few months between baseline and...
  15. C

    Adjusting for covariates in correlation test

    Hi, I wonder if it is possible to adjust for covariates when we use PROC CORR (correlation test) in SAS. Thanks!
  16. L

    sampling/probability/correlation?

    I have in my course this problem do you have any idea from people who work daily with stats ? the question is like that: the following data are available concerning the products of a firm taken at random from four factories, and classified according to level of quality: Factory A : from low to...
  17. S

    Can you use correlation for percentages?

    I have two variables: the number of employees who work from home in the firm and the number of independent contractors in the firm - and I have this data for 70 firms. I am trying to determine what statistical measure of association I can use to determine whether there is a relationship...
  18. C

    Should I be using ANOVA?

    Hi, I haven't done statistics in just over a year so trying to read through old notes and feeling a bit stuck! I'm running an experiment looking at pitch discrimination in both isolated notes and melodies, comparing both musicians and non musicians. 1) measuring pitch: should I be using...
  19. J

    correlation between group/factor level & individual scores with group means and MSE

    Hi everyone, I've been working on this problem for a couple hours now, and I'm stumped. Essentially what we have are 4 groups of 25 people each. The groups are formed around a sales goal for each group ($10k, $20k, $30k, $40k). We don't know the individual scores within those groups, but...
  20. M

    Joint Probability

    Hi All, I'm currently in a grad course with a nice complement of stats which we have been tasked to learn ourselves. Having some difficulties understanding joint probabilities. Specifically, I have a problem where we have 3 possible outcomes with probabilities p1=0.4, p2=0.1 and p3=0.5. If we...