-Is there any difference among suppliers? If there is,which supplier's product is best? Supplier 1 Supplier 2 Supplier 3 Supplier 4 18.5 26.3 20.6 25.4 24.0 25.3 25.2 19.9 17.2 24.0 20.8 22.6 19.9 21.2 24.7 17.5 18.0 24.5 22.9 20.4  Is there any difference among suppliers?  If there is, which supplier’s product is best? Supplier 1 Supplier 2 Supplier 3 Supplier 4 18.5 26.3 20.6 25.4 24.0 25.3 25.2 19.9 17.2 24.0 20.8 22.6 19.9 21.2 24.7 17.5 18.0 24.5 22.9 20.4