great question zweefer. normal ratio? all forage collection and the ratios will depend on and change according to the needs of a colony. many factors influence this, for example, the queen's age, laying ability, pheromone; the strength of the colony, eggs and larvae or lack thereof; empty comb, health of the colony, abundance or lack of pollen, nectar, water; temps and the time of year.
as far as deciding those ratio's, amazingly these decisions are made by the colony as a whole, and not just the house bees, through pheromones, communication and dances. foragers and scout bees play a pivotal role in the decision making. tom seely describes this as an "information center" strategy of foraging. mark winston (the biology of the honey bee) also describes two groups: (chapter on Collection of Food; Colony-Level Control of Foraging):
"Given the importance of food collection, it is not surprising that honey bees have evolved numerous mechanisms for increasing colony-level foraging efficiency. These mechanisms can be divided into two major groups: those for obtaining information about colony requirements and using that information to stimulate workers to forage for nectar and pollen; and those for allocating foraging tasks to maximize gain, recruiting to resources, transferring information and making decisions about when to switch resources."
this is a good chapter on food collection in winston's book.
also, seely's book, The Wisdom of the Hive, is an excellent in depth read of the organization of the food collection process in honey bee colonies.