A best-fit line
The data points are not exactly collinear. Least squares selects a line by minimizing the sum of squared vertical residuals, rather than forcing every point onto the line.
The Organic Chemistry Tutor · YouTube · 15:05
Calculate a least-squares regression line by hand and check the slope and intercept in a spreadsheet.
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The data points are not exactly collinear. Least squares selects a line by minimizing the sum of squared vertical residuals, rather than forcing every point onto the line.
The seven-point example uses sums of x, y, xy and x². Its slope is about 2.4142857 and its intercept about −0.828571; avoid rounding intermediate results early.
Spreadsheet SLOPE and INTERCEPT functions reproduce the hand calculation. Predicted values lie close to the observations but are not required to match each one exactly.
The data points are not exactly collinear. Least squares selects a line by minimizing the sum of squared vertical residuals, rather than forcing every point onto the line.
The seven-point example uses sums of x, y, xy and x². Its slope is about 2.4142857 and its intercept about −0.828571; avoid rounding intermediate results early.
Spreadsheet SLOPE and INTERCEPT functions reproduce the hand calculation. Predicted values lie close to the observations but are not required to match each one exactly.
The data points are not exactly collinear. Least squares selects a line by minimizing the sum of squared vertical residuals, rather than forcing every point onto the line. The seven-point example uses sums of x, y, xy and x². Its slope is about 2.4142857 and its intercept about −0.828571; avoid rounding intermediate results early. Spreadsheet SLOPE and INTERCEPT functions reproduce the hand calculation. Predicted values lie close to the observations but are not required to match each one exactly.
The computation requires the sums of , , , and .
Conditions: Computing the slope and intercept by hand for a least-squares regression line.
Least squares selects a line by minimizing the sum of squared vertical residuals, rather than forcing every point onto the line.
Conditions: The data points are not exactly collinear.