Average of multiple numbers

[trish logan]

I am trying to establish an error pattern for a comparison. I want to ask Access to look at my database and if there is an error then I need it to calculate an average of four rates so that I can take that figure to a further calculation. Here is my needed end result: The average of the four rate types times the units equals a total that is compared to another total. I am very new and coming from a business area needing to do IT related work that I am at a loss with.
Here is the formula:

County Auth Cost: (IIf(([Units Authorized]="1"), Avg(([Auth FT Rate 1)+([Auth FT Rate 2])+([Auth FT Rate 3])+([Auth FT Rate 4])),Null))

[Rabbit]

I don't understand; you seem to already have the formula.

[trish logan]

The formula is not working it says I have invalid arguments.

[Rabbit]

Did you remember to group by Units Authorized?

[NeoPa]

The Avg() function works across a domain of a single field or formula reference across multiple records. It appears you are trying to get the average of four Auth FT Rate fields within a single record. For this there is no function, yet it's a simple formula :- Simply add the values together and divide by four.