Line of Best Fit

Show anyone a rising cloud of dots and their eye sketches a straight line straight through it — no instructions needed. That imagined line is the line of best fit, and it's a superpower: once it exists, you can PREDICT. A student studies 5 hours — what score should we expect? Read it off the line. A house is 1,800 sq ft — what should it sell for? Read it off the line. The cloud shows the past; the line forecasts the future.