CREATE TABLE table_7440 ("geohash length" FLOAT, "lat bits" FLOAT, "lng bits" FLOAT, "lat error" TEXT, "lng error" TEXT, "km error" TEXT)

What is the lowest geohash length when the lat bits are less than 7, and the km error of 2500?
SELECT MIN("geohash length") FROM table_7440 WHERE "lat bits" < '7' AND "km error" = '±2500'
SELECT MIN("geohash length") FROM "table_7440" WHERE "km error" = '±2500' AND "lat bits" < '7'