1. S

    P-value of intercept = 0 meaning? Can age be independent var in simple regression?

    Hi I recently got into statistics... I am not too sure if this is the correct place to ask, I have included pictures as well Can I test "age of used vehicle" as independent variable against "selling price" as dependent variable in a simple linear regression? Is my residual plot as shown weird...
  2. N

    Is this a regression?

    I have 4 projects (Alfa,Beta,Gamma,Delta). The projects are rank from 1 to 4 based on personal feelings. Afterwards, the projects are evaluated based on 6 criteria (C1-C6). I want to find out what is the significance index of each criterion (how important was each criterion in the projects...
  3. K

    Probability limit of ridge estimator mu hat

    I have been working on the following question for a while but I stucked at a certain point. I have done part a and b and I found = (I_T + D'D)y where I_T is the identity matrix with dimension T, lambda is tuning parameter and D is the second order difference matrix which is a tridiagonal and...
  4. S

    Stata project JOB CASH WORK

    Hi, I am new on this forum and completely new to stata. PROJECT FOR MONEY Nevertheless, I am supposed to prepare a small project about alcohol consumption (in a couple countries - any) based on a couple variables like sex, type of alcohol, country, tax, GDP, etc. The project should consist of...
  5. M

    Most appropriate statistical method for master thesis

    Dear all, I'm currenctly doing my empirical part of my master thesis with title: Socio-Economic analysis of investment in Renewable energy. As a part of my research I would like to test 2 of my hypotheses: 1. Higher share of Renwables in energy mix reflects in lower Energy import. (EU-28) 2...
  6. M

    Finding the worst mobile phone by Regression and Data Mining

    we have about 50000 models of mobile phone (like Galaxy S7, iPhone 9) in database and the size of data is about 3 million. We want to find the mobile phones that have the least call success rate ( the numbers of successful call divided by total call). We want to run a Regression model to find...
  7. V

    Compare the estimated model with the model with intercept-only

    The question is: How do the test to compare the estimated model with the model with intercept-only ? How can I comment on the result ? I think we need to calculate the test F... I read several notes, but I can not understand how I do . The idea is to take Null deviance and Residual Deviance...
  8. V

    Find costant that satisfies the variance

    Hi, I have this regression model : Y_i=B_1+B_2logx_i+2e_i e_i~N(0,σ2) I am asked to find the constant : Y∗=y c that satisfies V(Y∗)=σ^2 I have some doubts ... I would say that the constant is equal to 1/2 ?
  9. C

    Defining Contrast Matrix

    Suppose I have a binary Covariate X which is defined as X = \begin{cases} 1, & \text{if treatment group} \\ 0, & \text{if placebo group} \end{cases} The model is \mathbb E[Y] = \beta_0 + \beta_1X, where Y is a continuous random variable. If X=0, then \mathbb E[Y] =...
  10. S

    p value of the constant, can I ignore it?

    I'm analysing the influence of various factors on hare harvests in a specific are. E.g. How do the hare harvests change when the fox harvests increase. Term Coef | SE-Coef | T-Value | P-Value Constant | 415.0 | 28.7 | 14.46 | 0.000 Annual fox harvest | -1.054 | 0.193 | -5.45 | 0.001...
  11. spunky

    range of possible values for regression coefficients given another one?

    i feel like the answer to my question is a 'no' but i'll ask it anyway just to be absolutely sure. say you have 3 variables X, Y and Z each one with some correlation r_{xy}, r_{yz}, r_{xz}. we know from the formula of the determinant of the correlation matrix that if, for instance, r_{xy} and...
  12. J

    Data problem

    I need a little help about a guidance how to represent "unlimited" as a value in regression variable. For example, some phone plans includes finite amount of free minutes, but some include unlimited minutes. Therefore, I have a variable "free_minutes" but I don't know how to properly...
  13. R

    Logistic Regression Model Assessment

    I have run logistic regression on data. The concordant percentage is coming out 45. That is too low. However, Hosmer–Lemeshow test is coming out insignificant. It means we cannot reject the null hypothesis stating model fits the data well. That's good! The ctable also shows 70% of the data...
  14. A

    Plz help...LOG transformation of Ratio in Percentage Independent variable

    Hi, In my regression I have used a ratio term (in %) as the independent variable. That value ranges from 0.0001% to 99.95%. Can I take the log of this variable to normalize the variable. Plz help. Thanks in advance
  15. K

    Need method for analysing two sets of time course data

    Hello, I have two sets of time course data, they are for an eye-tracking study. The data is 20 100ms chunks, one category being percent fixations for canonical sentences, and the other being percent looks for non-canonical sentences. I would like to curve fit this (I believe the logistic curve...
  16. E

    Cross-estimating the independent variables to exclude outliers

    I am working on a dataset where some of the independent observations have measurement issues (i.e. mixed feet and metric). I'm considering cross-estimating all the variables to exclude outliers before building the actual model. In other words, a method for defining and excluding outliers and...
  17. U

    F-value (ANOVA)

    Hello, May I know what does the F-Value in ANOVA implies? Thanks:)
  18. Z

    How do I interpret regression coefficients when there are log transformations?

    Hi, I'd like to know how to interpret with percentage the slope coefficients of a regressoin when I have: A- log(Y) ~ log(X) b- log(Y) ~ X c- Y ~ log(X) So far I found this web site, but I'm not sure it is accurate:
  19. M

    Estimating Covariate Effects on Likert-Scale Response Data

    I am working on a problem where we elicit medical residents perceptions regarding the importance of specific core medical competencies (professionalism, collaboration, medical expertise, etc.) on a 5 point Likert scale. For example, "In your current residency role how important is...
  20. C

    Which regression model to use with skewed & ordinal data?

    I'm a bit stucked and just wondering about which regression technic to use with my dependent variable at hand. Respondents were asked to provide a particular percentage value from 0-100. Sadly, these percentages are not accessible in the dataset, but were ranked into nine categories (0-8). The...