average every 10 minutes worth of data and delete the rest
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For example I have a table that has the number of people in a room at a given time

    room_color    people    time
    red           100       2012-07-13 11:11:11
    red           120       2012-07-13 11:14:12
    red           130       2012-07-13 11:17:13
    green         ... etc

How do I find the average amount of people in the room in a 10 minute interval, for example to summarize the amount of people in the red room at 11:10 to be ~117

I know some ways to do this but it all involves creating a new table, how do I do this without creating a new table? I simply want to delete irrelevant data.