Jill
There are two forms of analysis - Guaranteed and Typical.
Guaranteed analysis - the figures given are the minimum/maximum (as specified) that the product will be. ie: If moisture gives a 9.5% maximum analysis then the moisture will never exceed 9.5%, but can be lower, if protein gives 25% minimum, we will never go below 25% protein, but will range above this.
Typical analysis (no minimum or maximum quoted), but the figures given are what the product aims for and the product will be + or - 2% variable. The moisture, fat or protein can be either 2% above or below this figure.
There are always variables in food manufacture. An example would be if we all made a fruit cake from scratch with exactly the same ingredients and made the same way, the degree of moisture, colour and tase could (and probably would) vary due to storage of ingredients, whether our weighing scales were accurate, utensils used, time taken to mix and variable oven temperatures. Trust me on this - I used to make a lot of fruit cakes and some were better than others even though I followed exactly the same recipe.
Most 'reputable' pet food manufacturers regularly analyse their batches to ensure it meets the specs. If there were discrepancies, you can bet that a competitor would be lodging a complaint with the Pet Food Industry Australia.
Whilst price is often an indicator of quality, it's only one factor.
Cheers