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[2026-08-21]Rahulupdated 2026-08-21DATA-SCIENCE

One regression, 140 years of machines

Galton, 1886: predict a child's adult height from the parents'. Same 928 rows, same five sums, same line. Only the machine changes.

child = 23.94 + 0.646 × midparent. Galton 1886, 928 children, circle size is count.
rows
rows done0
Σx0
Σy0
Σx²0
Σxy0
slope b·
intercept a·
elapsed on this machine
0
machine method limit
how the numbers are computed

Time = fixed setup + rows × seconds per row, capped by what the machine could hold. Per-row seconds come from: checked three-digit products by hand (Grier, When Computers Were Human), Brunsviga and Millionaire crank rates (Campbell-Kelly, History of Mathematical Tables), IBM 601 card throughput (Eckert 1940), IBM 533 card reader at 200 cpm, IBM 370/158 at 1 MIPS with 3420 tape, Intel 8087, Lotus 1-2-3 Release 2 and Excel 2007 row limits, numpy on an M3. Prices are period list or rental, CPI adjusted to 2024. Pre-1950 rates are estimates. For row counts above 928 the Galton rows are repeated. Galton drew his own line by eye from a 102-cell table; least squares on this data starts with Pearson, 1896.