sorry i had to fix a number here - its ok now

" fish number fish weight sum3-4 sum 4-5
31457 3.5
45367 4.5
34289 3.5

sum 3-4 should return sum of the two rows with between 3 and 4 (230111)
and sum 4-5 shold return sum sum of the row with 4.5 (204151)