How to compute an average over a date-span instead of an item-span
I'm a new user of FMP 11 on a Mac under 10.6.2.
I have a table format that is created by an outside program and imported into FMP.
For the purposes of discussion it has these columns:
Item Type (text)
There are typically many entries with the same Date and WeekNumber differing by Item Type and Calories.
I would like to average Calories over the span where WeekNumber is the, totalling Calories for each Date and then writing an average Calorie number for the week. Unfortunately the Average summary, when applied to Calorie gives me the average for each ENTRY. I cannot figure out how to do arithmetic on a summary field in a report or failing that, how to do a collect the data in such a way as to allow the use of the average summary field.
Thank you for any ideas. I don't think I'm thinking like Filemake Pro yet!