Averages for Dummies?

[Jenniesue30]

I am a complete novice to Access. I have been setting up my data base by trial and error. I think I have been doing a pretty good job of it till I wanted to average out my columns. On some of the drop down menu's I do see that Average is an option but it is greyed out to me. I have looked up tutorials online but I do not understand them.
Is it possible someone can give me the "Average's for Dummies" version.

Not sure if it will help, but I have included a screen shot of the form. (if you can read it.)

Thanks in advance

Jennifer

 

[pbaldy]

Try this as the control source of a textbox in the group or report footer:

=Avg(FieldName)

 

[Jenniesue30]

Thank you Paul for your suggestion.
Like I said in my first post. Access for Dummies.
Here are the steps I am doing. I cannot get it to work
1. On my report I click on Design View.
2. On the Design Tab I click Text Box.
3. I click on the unbound box. I then go to the Property Sheet and click on Data.
4 In control source I click the first drop down and pick which column I want to use. I then click on the second column and type in =Avg([Gelcoat]).
When I try to go to Report View I get The error "Data type mismatch in criteria expression"
If there is some type of documentation that does it step by step I would really appreciate it.
Thanks again for your help
Jennifer

 

[pbaldy]

You appear to be doing it correctly. What is the data type of that field? Can you post the db here?