correlation

  1. A

    Why does a larger sample size produce a smaller p-value?

    Hi, I need help with this problem... The obtained p value for a correlation analysis is .036, for a sample size is 50. If the analysis had been undertaken with n = 90, and the same sample correlation value was again observed, what would be the relative size of the p value for the second...
  2. X

    Find correlation when SD and mean are given

    A guy got 88 in his test which has mean score of 64 with SD 8. He missed the second exam in which the meanscore was 45 and SD was 5. He got a prorated marks of 55. The prof used regression to get his second test marks. What was the corelation between 2 exams ? P.S: I would really appreciate...
  3. G

    Correlations among responses to a forced-choice scale

    I have data from participants who rate emotional content of pictures. Specifically, people see 20 pictures of abstract paintings (one at a time) and are asked, "what emotions is expressed in the picture?" There are 5 response options: anger, fear, sadness, happiness, and none. The key info here...
  4. I

    setting parameters in G*power for correlation tests

    Hello, everyone :) Need your help on how to set parameters in G*power... I am doing two very simple tests: one on pearson correlation between midterm scores and quiz another one on partial correlation between the same scores with motivation score as controlling variable. I need to run a...
  5. B

    Online-estimate of squared correlation coefficient for linear optimization

    Summary: Is there a way to directly estimate the squared correlation between two zero-mean Gaussian variables on-line and without storing more than two samples at any given time? Dear all, I am working on an optimization procedure to minimize the correlation between two zero-mean normally...
  6. T

    Correlation and significance with dependent observations

    Hi, I am trying to correlate two variables of which one variable has dependent observations as it is data derived from a social network. I am intending to use Spearman's rank correlation coefficient. As I understand conventional methods for significance test do not provide reliable results...
  7. W

    Trying to evaluate/measure how much 1 variable affects another.

    Hello. So I've been helping look at some data for a fundraising event my school ran. We used an app and the school wants to evaluate if it is worth it. From the event I have the data of all donations (how much it was and who it went to). So what was done is for all fundraisers the sum of all...
  8. J

    Whats the best way to analyse the correlation between these two variables?

    Hello All, I have to admit my statistics skills are not amazing however, i'm very interested in improving my knowledge. I've been trying to work out a way to see if there is a correlation between the number of troops in iraq and Afghanistan (BOG) and the price of an index that only deals in...
  9. S

    Searching for analysis that would compare two trends of data

    How to find correlation between two curves Hello, glad to be here. I am looking for an appropriate statistical analysis to address a problem similar to the one described below: Lets say I want to find out how a performance on one test correlates with a performance on a different test across...
  10. M

    Correlation multivariate trinomials

    I have a dataset of 6 multiple choice questions with each question having 3 mutually exclusive choices. The dataset is split into a number of time frames where each time frame hold, say, 1000 questionnaire results and each of the 18 datapoints provided in the time frame hold the fraction of...
  11. N

    Looking to see if there is a correlation between qualitative and quantitative data

    Hi, I have an environmental science issue where I'm trying to see if there is a correlation between some qualitative and quantitative data. (Hopefully I'm posting this in the right place). Basically at my work we have ecological contractors who assess whether particular natural areas have...
  12. B

    Correlating values to different characteristics

    Hello, I'm trying to figure out the best way to correlate a number of values against a set of discrete characteristics for a small population. In the attached example I have 3 different sets of values and two different characteristcs. It is obvious to the eye that the first two sets of values...
  13. C

    Correlation?

    Hello all, I have accuracy scores on 6 different tests. I have calculated the percentage of the accuracy in each test so that each of the tests has a score on the same scale (0-100%). I want to see how well do each of the 6 different tests correlate with a 7th test. I have been told I should...
  14. V

    Correlation based on binary events

    I have a system with 5 components. Every 10 seconds the signal travels to all of them and I know how many of them responded. I need to know there there is a correlation in response. So, my time series data looks something like: A B C D E ----------------------- 1 0 1...
  15. E

    Time series help, Derive COV in a random walk process

    I could use some help deriving the covariance between Y_t and Y_t+h given the random walk process Y_t = Y_t-1+e_t And also the correlation between Y_t and Y_t+h Got stuck.. :( Also got another problem where i need to state whether pbl_t is correlated with e_(t-1) in this regression q_t=...
  16. F

    Confused about Correlation Terms

    Hi, I am confused about different correlation terms. Can you help me? Difference between Cross correlation, Serial Correlation and Seasonality Thanks
  17. K

    statistics help please

    I'm having trouble with a few questions in my text book and was hoping you could help...I need to know this for my exam and I just need some help figuring these out...the first one is 1. A two-factor research study has two levels of factor A and two levels of factor B with n = 10...
  18. J

    Statistically analyze fluctuating relationship

    Hi guys, I've entered some uncharted territory and I'm not sure how to proceed. I need to quantify how two variables fluctuate together over time. In my study, I had ten sequential blocks of trials on a psychological task (block 1=first, block 10=last). For each block of trials my DVs are 1)...
  19. B

    Excel and StatPlus to do Multiple Regression

    Hi all--I would be grateful for any help with this! I am doing my statistics research project on whether or not there is a correlation b/w where consumers do their grocery shopping and how sustainable they are. I did a quick, 6 question survey to 10 shoppers at 3 grocery stores (for a total...