linear regression

When conducting a simple linear regression analysis with one categorical predictor variable and power projected at .80, G*Power suggests a minimum sample size of n = 55. Now, assume that the predictor has three categories, and that I obtain 55 necessary responses. What does it mean for the...

Hello, I am running three multiple linear regression models. In all three, the dependent variable is the democracy index score of a range of countries over several years that the EU has agreements with. I use three independent variables in each model. Two of those are the same in each model: a...

Hello, I am an MBA student and require help doing a multiple linear regression analysis using spss, check if I uploaded the data with the correct options and how to interpret the data and results. I have 2 independent variables and 1 dependent variable. Thanks!

I'm currently trying to understand the relationship between firm performance and various independent variables (e.g. firm size, firm profits..). Now, the regression I'm estimating looks like the following: Δlog(firm_performance) = α + β1 Δlog(firm_size) + β2(other_variable) + ε Where Δ...

How can I handle heteroskedasticity?

Hi, I am not really able to understand whether the basic assumptions of linear regression are met (I'm kind of a novice). I have a dataset that is big enough (as far as I understand), a series of significants coefficients (both individually and togheter) and an adjusted R-squared over 0.9...

Hello, I am currently working on a study about how much time a chess engine should think per move in a chess game. The inputs (known data) would be how much time is left (in seconds), the evaluation of the engine (centipawns) and the move that is being made. My question is: is it a multiple...

Hi, I am currently studying Zoology at university. I am currently in my final year conducting my dissertation. I have completed my data collection and I am now on to my statistics. My dissertation looks at the relationship between light intensity and growth rate in marine sponges. I have 5...

Hi, I tried to calculate the minimum sample size for multiple linear regression. I tried to check the sample size for predictors=4, effect size f=0.2/d=0.2, sig.level =0.05, power=0.8 1. When I checked the power of the entire model (F power) n=304 2. When I checked the power of one...

Hello, I performed a simple linear regression analysis in Matlab and am unsure about how to report the results. I definitely mention the coefficients and the p-value, but do I mention the t-statistics as well? And if so, how exactly? This is an example Matlab output:

Hi, I performed a linear as well as a logistic regression analysis (both with Matlab) and plotted those. Now the logistic regression curve is very linear and can be described by the same function as the linear regression. I explain the linearity by the fact that it is only a very small fraction...

I am performing an engineering analysis to find out the effect of earthquake on concrete buildings. Analysis applies earthquake forces on building model for 50 earthquakes, resulting into separate 50 analyses. Earthquake intensity is independent variable of study. building drift, extracted from...

Dear All, I am searching for the association between a phenotype (PHEN) and the additive genetic model (ADD, with the values 0,1 and 2) with two adjustors, Year of Birth (numeric) and COUNTY (catergory). The data has been weighted for the year of birth. In R I use the next command...

Hi everyone. The table above contains two example factories that I would like to test for cointegration using the augmented dickey-fuller test. I intentionally use this short time series because I want to do the calculations by hand. Below you will see my attempt to carry out this procedure and...

Hi, I need some help with a modeling query: I have fit 100,000 linear models: M ~ age + age^2, M is the frequency. I found 2,000 models were significant, but would like to narrow it down to find the most ‘extreme’ cases. Is this possible? Does anyone have any suggestions or any references...

Hello to everyone! :wave: I should do some regressions but i've an important and simple question... my dataset have this structure: |geographic_area|year|sales|popolation| Spain 2000 40 1000 Spain 2001 30 2000 Spain 2002...

I have a question that is and R question and a statistical question: I am analysing sales of a retailer. These sales are related to some vars: var1, var2, var3.., varN Most of the vars are continuos. I want to analyze the relationship between sales and the vars. I have made a linear...

In SPSS, how does one go about trichotomizing an independent variable such that about 33% are in each of the three groups?

Hi there, I'm interested in the effect of several variables on severity of schizophrenia symptoms. I want to look at the effect of 9 predictor variables in a regression model. Severity of schizophrenia symptoms is the outcome variable. My sample size is about 60. My 9 predictor variables...

I did an exam recently and I am looking for a solution to a question which no matter where I look, I can't find out how to do it. It doesn't help I'm not very good at stats hence the post here. Could someone maybe point out a Youtube video that deals with similar problems. It's specifically part...