Mathematics, Statistics & Geometry

Multiple Regression Calculator

Perform advanced multivariate OLS regression. Calculates exactly how two independent variables (X₁, X₂) jointly affect a dependent outcome (Y).

Regression Equation
y = 1.0667 + 0.5333x₁ + 1.6667x₂
Intercept (b₀)1.067
Coefficient 1 (b₁)0.533
Coefficient 2 (b₂)1.667
Calculation StepsInputs: N = 5 datasets Using Ordinary Least Squares (OLS) for multiple variables: y = b₀ + b₁x₁ + b₂x₂ Sum of Deviations: S₁₁ (x₁ variance) = 10.0000 S₂₂ (x₂ variance) = 14.8000 S₁₂ (covariance) = 10.0000 Solving via Cramer's Rule/Matrix Inversion: b₁ = 0.533333 b₂ = 1.666667 b₀ = 1.066667

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Multivariate Predictive Modeling

The Multiple Regression Calculator is the engine behind advanced data science. When predicting complex outcomes, standard lines fail. This tool utilizes matrix-based OLS to fit a perfect 3D mathematical plane to your scattered multivariable data.

Y=b0+b1X1+b2X2\begin{aligned} Y = b_0 + b_1 X_1 + b_2 X_2 \end{aligned}

Where:
Y=
The outcome you are trying to predict
b1,b2b_1, b_2=
The weight or 'importance' of each specific variable
b0b_0=
The baseline value of Y when all X variables are zero

Isolating Variables

The true superpower of multiple regression is its ability to statistically 'control' for variables.

Imagine you are trying to find out if taking vitamin C prevents colds. You track vitamin C intake (X1) and the number of colds (Y). However, people who take vitamins might also wash their hands more (X2). By putting both X1 and X2 into a multiple regression, the algorithm isolates the exact effect of the vitamin C independent of hand-washing.

Real-World Applications

  • Real Estate Appraisal: Predicting the price of a house (Y) based on its square footage (X1), number of bedrooms (X2), and the crime rate of the neighborhood (X3).
  • Sports Analytics: Predicting a baseball player's future salary based on their batting average, home runs, and years of experience.
  • Public Health: Determining how much life expectancy is affected by smoking rates, controlling for income levels and access to healthcare.

Frequently Asked Questions

It is an extension of linear regression that uses two or more independent variables to predict an outcome. Real-world events are rarely caused by just one factor.

They tell you the isolated effect of one variable. If b1 is 5, it means that for every 1 unit increase in X1, the outcome Y increases by 5, ASSUMING X2 stays perfectly constant.

It occurs when your independent variables are highly correlated with each other (e.g., using 'Left Shoe Size' and 'Right Shoe Size' to predict height). It crashes the mathematics of the regression.

It uses multivariable Ordinary Least Squares (OLS) combined with Cramer's rule matrix inversion to find the coefficients that minimize the squared error in 3D space.

Not directly. Categorical data must be converted into numerical 'dummy variables' (e.g., Red = 1, Not Red = 0) before running the regression.