M1 · The Best Straight Line
Fit It by Eye First
Place a line through points by hand and say what makes one line better than another.
Twelve delivery runs are on the board. Distance across, minutes up. Your eye finds the line in about a second. It does not do arithmetic. It just sees where the band of dots is heading. The hard part is not drawing the line. The hard part is saying, in a number, why your line is better than mine.