correlation coefficient

  1. T

    Pearsonn Correlation Coefficient of Averages

    I have a question regarding using PCC in a specific scenario. Suppose I have 10 subjects of different ages. I want to know if there is a correlation between age and a specific parameter. That parameter for example is the area of pituitary cells. So in essence I want to know if there is a...
  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. B

    Weighted values from correlation coefficients

    I've been pressed to find a similar existing example of what I'm trying to do, but maybe i'm not phrasing it incorrectly. Essentially, I want to do a dynamic pricing model. Create a formula where i take the correlation coefficients of various variables related to pricing, and then when...
  4. H

    Should I use Pearson or Spearman correlation?

    I have to know whether two variables are correlated or not in a sample. None of them are normally distributed, so I assumed that I should run Spearman's correlation, which gave me a correlation coefficient of 0.392 (p<0.05, and Pearson's correlation was equally p<0.05). My problem is that now I...
  5. D

    Determine whether the product moment correlation coefficient changes Can someone please help me with part (e) to determine whether the product moment correlation coefficient increases, decreases or remains the same. Here is what I think. Although the new Syy increases with the addition, we cannot...
  6. T


    I have a list of 100 observations. One variable describes the sex of an individual (male or female); the other variable describes the number of times the individual blinked during the observation. (30) of the (100) observations are with men and (70) are with women. Sample sheet attached. How do...
  7. S

    Interpretation of r and r^2

    I am doing regression analysis on two stocks. The correlation coefficient is -0.7190 and the coefficient of determination is 0.5170. I am confused on how to interpret this. Is this correct...when stock A goes up 1%, 50% of the time stock B will go down 0.72%?
  8. L

    A question about Spearman's Rank and Mean Values

    Hello, I'm not entirely sure I've put this in the correct forum... This is possibly a daft question, but I have used SPSS to calculated Spearman's correlation for a series of data sets and I was wondering if I can average the correlation values to give an average r result? :confused: I...
  9. B

    Fisher r to z transform / significance test for two different values of r^2

    Short version: I have two values of r^2 from Pearson's correlation, one from a control group (.713) and one for an experimental (.527), and I would like to quantitatively compare the difference in how well/poorly the points in each group cluster around their fit line. Long Version: The data...
  10. R


    Hello, I had to miss my last class in stats and I don't know how to solve this question. 1. For each of the following combinations of values, decide whether the combination is possible or impossible, and if it's impossible, explain why. a. b = .80, sy.x = 0, r = 1.00 b. b = .80, sy.x =...
  11. 8

    How to derive R-squared from correlation coefficient?

    How to derive R-squared from correlation coefficient? I need it very much please help
  12. I

    Summing Uniform Distributions

    Hi, I can't seem to work out (or find anywhere) how to add two independent uniform distributions. My problem is as follows: I have random variable X~Unif(0,13), and error Z~Unif(-0.5,0.5) which is independent of X. I need to find Y=X+Z, the joint pdf of X and Y, as well as the...
  13. K

    A little Help

    So I'm doing this stats project. My project was to test how far(inches) a toy car can go off a ramp of five different heights (5, 10, 15, 20, 25 degrees) and I did this test six times for each height to get 30 data points. (These were my distances 72.25, 73.5, 79.25, 79, 76.25, 81.625, 94...
  14. J

    How to calculate "expected" value given correlation coefficient, etc.?

    I have two independent variables: number of stores per metro area (about 100 areas) and number of actual visitors. I was able to figure out (or rather had Tableau figure out) that the two have an R-squared of 0.61 (r=0.78), so there is a strong correlation, which I would expect. I also have...
  15. A

    How to Compare three Data Series Collected by different means?

    I need to compare three different data series. The subject of the data is the same, but the collection method is different. My initial approach was to only compare two of the series at a time, using Kendall's correlation coefficient. I chose this because it seemed like the best method to...
  16. M

    Help with correlation and coefficient

    Hi just wondering if anyone could help me out with this question that I'm stuck with, it's a question from the past exam paper that might come up this year and I'm really struggling. If you could even just tell me the way of doing it or the formulas needed for it,I'll do the calculations...
  17. P

    Correlation coefficient of X Y,Z

    the correlation coefficient of X Y is 0.6, and the correlation coefficient of Y Z is 0.7, what is the range of the correlation coefficient of X and Z?
  18. S

    Interpretation of correlation coefficient

    Hello, I am working on a meta-analysis with the program R. Here I am investigating the relationship between the dependent variable "participation in Lobbying" (results = yes or no) and the independent variable "company size" (result = value of assets). The result I got is an Fisher's...
  19. S

    Compute score from variance or correlation coefficient?

    Greetings, I’m seeking inspiration in creating a scoring (figure of merit) function that can evaluate how close a set of parallel measurements are to a set of truth values. The truth values aren’t a statistical mean per say, but rather target values being sought. A set of measurements...
  20. E

    Intraclass Correlation Coefficients: Significant Difference when H0~=0?

    I'm trying to determine whether two intraclass correlation coefficients are statistically significantly different. The catch is that the two samples are between subjects, and the null hypothesis is that the difference between rho1-rho2 = .5. I've done a Fisher's Z' transform, but the confidence...