The manager of a carpet store is trying to determine optimal installation crew size. He has tried various crew sizes with the results shown below. Compute the average labour productivity for each crew size. Which crew size do you recommend?

$\backslash$table$[[$Crew Size,Yards Installed$],[2,706],[4,1,308],[3,1,017],[3,1,002],[4,1,288],[2,692]]$