GOAL: To create a field in my access report that includes the Average Wait Time for all students serviced on a specific date.

REPORT SPECIFICS: My first column shows the DATEHELPED, second column shows the NUMBERSERVED during that day. I'd like a third column that states the average wait time on each day.

I have a TIMESIGNEDIN field and a TIMESERVICED field in my table. I created a TOTALWAIT expression in my query as follows: TOTALWAIT: Format([TIMESIGNEDIN]-1-[TIMESERVICED],"Short Time"). This part works, showing me the total wait time for each individual person.

PROBLEM: Now I'm attempting to come up with the average wait time for all students on each day by using =AVG([TOTALWAIT]), but keep getting a "Data type mismatch in criteria expression."

My report is grouped by DATEHELPED from oldest to newest. I've been attempting to calculate the TOTALWAIT in the DATEHELPED grouping so it is on the same line as the rest of the data.

I would so appreciate your help with this. I'm sure there is an easy adjustment I'm just not coming up with at the moment.

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Reply from Richard Rost:

Make another calculated field called TotalWait2 that shows the total wait time, but don't format it as a time. Leave it as a number. =TimeServiced-TimeOut. Now you have the number of DAYS (probably a fraction) which you can convert to minutes or seconds if you want with a little math. Now, put =SUM(TotalWait2) in the FOOTER (group footer for your report, if you want). This will give you the TOTAL wait time. With a little math you can divide the number of students and there you go - average time. I cover stuff like this in my classes like AC220, AC305, etc. Just search on FOOTER and you'll find lots of examples.