linear regression

  1. P

    Linear Regression Multiple Choice Questions: Please Help!!

    I have attached my practice sample final for my college statistics course on linear regression. All of the answers are multiple choice, and I need help finding the right answers for questions 5-39 as soon as possible. Please, please, help me if you can, as soon as you can! I need the right...
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    Regression with missing data

    Hi all So I just want to do a quick linear regression, but when I initially tried I had an error (r(2000 no observations). I've realised my issue was that I have several variables with missing values. I have a 3-level dependent variable (1,2,3). Then I have several variables that indicate...
  3. M

    Linear regression vs logistic regression

    I have a time series dataset. The, X (Independent variable) is time and is denoted as 1,2,3,4,5,6..1000.etc Y (Dependent variable ) is a percentage scale as 99%, 98.7%, 96%, 91% ...etc. This is a continuous data set. I have 1000 such data points. The first 700 data points used as training set...
  4. U

    Which SSR (Regression sum of squares) is theoretically larger?

    Dear all, I have 3 fitted lines: Y = b0 + (b1)X Y = (0.5)b0 + (b1)X Y = b0 + 0.5(b1)X Where and In addition to the the 3 equations above, using the information provided by the image attached I would like to determine (theoretically), which one of the three fitted lines (listed...
  5. U

    Two variable OLS Regression - using normal equations

    Hi, I am experiencing difficulties in understanding the following question; I have been assigned two variables (X and Y), and have been given a data-set which consists of 50 data entries for both variables X and Y, ranging from 15-60. I have also calculated ƩX, ƩX^2, ƩXY and ƩY. Essentially...
  6. S

    Linear regression on data with standard deviations?

    (crossposting from here) I am trying to do many linear regressions on series of data points where each data point is associated with a standard deviation. For simplicity sake, let's say that each series has 3 points (of mean measurements), each of which has its own standard deviation. Series...
  7. K

    N of 1 study looking at complex phenotypes and SNPs

    Hi All, I have a complicated question and can't find a resource that answers it comprehensively. I'm designing a study looking for linkage between a complex phenotype; how people respond to various different topical treatments. This will not be published in a scientific journal so will be...
  8. B

    Power analysis and sample size

    Hello all, I've used perused this site numerous times in the past for assistance with statistical issues, but this is my first post. I work with fish, and am specifically interested in the environmental effects on these fish. I ran regressions of growth increment (growth experienced in a...
  9. D

    Help with linear regression when multiple subjects

    Hi, I have some data where each subject is presented with pairwise combinations of four test items (A, B, C and D). Each observation is a subjective difference between the two items (the exact details of the experiment are not necessary but I can expand if it helps): obs(A, B) = A - B...
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    Ranking a Location using Linear Regression

    Hi, I am facing a strange problem with a software patented in the USA. It is a location evaluation software, which offers insights on determining the best location for starting-up a gas station / petrol station. While reading the patent thoroughly, I feel that the software operates based...
  11. L

    Finding correlation for penalized regression in R

    I need to use the penalized models (lasso, ridge) for linear regression. In R, I use the "penalized" package. The output is a penfit object. If I want to find the in-sample and predictive correlation, how can I do that in R? Converting the penfit oject to glm maybe a good idea,but I don't...
  12. K

    How to correct for autocorrelation in Excel

    I do not understand how to correct for autocorrelation. One website easily describes how to do it in excel however I could not find any sources to verify this: https://analysights.wordpress.com/tag/data-analysis-using-microsoft-excel/ This is the site that explains how to correct, however...
  13. D

    Regression and imputing zeros

    Hi all! I have what is likely a simple regression problem. I am imputing Variable X from survey Y to survey Z. I am using a simple linear regression model and the predict function in STATA. So, I run a regression on Variable X in survey Y, using a host of independent dummy variables...
  14. V

    ARDL model in STATA

    Hi to all, I am also using the ARDL in my model. So I used the varsoc variable to determine the optimum lag for my variables, than I used the ADF to test whether my variables have a unit root or not and also I used the Zivot-Andrews test for structural breaks. Now I am struggling with the...
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    Violating Linear Regression assumptions

    I have a dataset in which I am performing linear regression with multiple covariates. The goal of the analysis is to identify important covariates (categorical and continuous) which have an important effect on the response. This is a natural resource dataset so it is not as clean cut as other...
  16. R

    Pearsons Correlation, Two-way ANOVA, Linear Regression Test, Chi-Square Test or None

    During research, you have asked your participants whether or not they have ever experienced financial difficulties (yes or no). You have three age-groups (16-20; 21-25; 26-30), and you predict that those in the 26-30 group have a greater risk of experiencing financial difficulties than those who...
  17. R

    Linear Mixed Model, a Regression type Statistical Analysis or other?

    I have performed a study on stability where my outcome is continuous and the two inputs are ordinal. Essentially: I am trying to understand if the weight location in a backpack (high, medium, low) and the grade of the road (0%, 5% and 10%) are related to significant differences in stability...
  18. P

    Propagate error with prediction interval

    I have a linear dataset with known values of X & Y in R. I treat the dataset as a linear model. I have a data point with a known value of X and an unknown value of Y. The X value has an associated instrument error. Goal: compute the prediction interval (of Y) for the data point based on...
  19. P

    How do propagate error associated with input variable

    Hello! I have a linear X,Y dataset in R. It is being treated as a linear model [g=lm(Y~X)]. What I want to do is input a specific value of X along with its associated error and determine the prediction interval. To do this without propagating the error associated with the variable, X...
  20. S

    Replication in linear regression. General Estimating Equations (GEE) a good option?

    or is it the only option? I've been collecting hosts in 3 different habitats, about 20 hosts every sampling trip. I've been recording prevalence of a parasite (1 or 0) and abundance (number of parasites per host) for each individual. I'd like to know: Abundance/prevalence (DV) are the...