CREATE TABLE table_203_808 (id DECIMAL, "rank" DECIMAL, "peak name" TEXT, "elevation" TEXT, "location" TEXT, "notes" TEXT)

how many feet separate the 7th and 8th ranked highest peaks ?
SELECT (SELECT "elevation" FROM table_203_808 WHERE "rank" = 7) - (SELECT "elevation" FROM table_203_808 WHERE "rank" = 8)
SELECT (SELECT "elevation" FROM "table_203_808" WHERE "rank" = 7) - (SELECT "elevation" FROM "table_203_808" WHERE "rank" = 8)