LR8-01-CYU5 (Lines of Best Fit)

① This interactive GeoGebra example demonstrates how to draw a line of best fit on a scatter plot, with automatic feedback on the user's drawn line. ② Core mathematical concepts include linear regression, scatter plots, residuals, and the intuitive idea of minimizing vertical distances between data points and the line. ③ Construction highlights: the FitLineY command computes the least-squares regression line; Polygon and PointIn are used to check whether data points lie above or below the user's line; Zip and Element manage point lists; LaTeX renders the question text; Line and slider-like variables enable interactive dragging; script variables (questionList, currentPoints, lineOfBestFit) support multiple randomized questions. ④ Suitable for middle school to high school students learning statistics and linear regression, as well as for classroom demonstrations or self-paced practice to connect visual estimation with formal regression methods.