Scatter Plot Maker — XY Correlation & OLS Linear Regression Graph
A scatter plot maps paired numerical variables $(x_i, y_i)$ onto a two-dimensional Cartesian plane to reveal linear or nonlinear correlation, clusters, outliers, and least-squares regression trends ($\hat{y} = mx + b$).
Tip: Paste Excel or Google Sheets rows (Ctrl+V / ⌘V) directly into any cell.
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OLS Slope: m = sum((x_i - mean_x)*(y_i - mean_y)) / sum((x_i - mean_x)^2). Intercept: b = mean_y - m * mean_x. Coefficient of determination: R^2 = 1 - (SS_res / SS_tot).
Chart Design & Use-Case Tips
- 01OLS Slope: m = sum((x_i - mean_x)*(y_i - mean_y)) / sum((x_i - mean_x)^2). Intercept: b = mean_y - m * mean_x. Coefficient of determination: R^2 = 1 - (SS_res / SS_tot).
- 02Place the explanatory or controlled input variable in Series A (X-axis) and the measured response variable in Series B (Y-axis).
- 03Inspect the dashed OLS regression line and R² coefficient rendered automatically on the canvas to quantify linear correlation strength.
- 04Look for points far removed from the regression line to identify high-leverage outliers.
Frequently Asked Questions
How do I enter X and Y coordinates in the table?+
Enter the X-coordinate in the first numeric column (Series A) and the corresponding Y-coordinate in the second numeric column (Series B) for each observation row.
What does the R² value on the scatter plot mean?+
R² (coefficient of determination) ranges from 0 to 1 and measures the proportion of variance in Y explained by a linear relationship with X. An R² above 0.80 indicates a strong linear fit.
Does correlation on a scatter plot prove causation?+
No. A high R² confirms mathematical covariation between X and Y, but establishing causation requires controlled experimentation or domain verification.