The Lumber Division of Vaughn Manufacturing produces and sells lumber that can be sold to outside customers or within the company to the Construction Division. The following data have been gathered for the coming period: If the Lumber Division sells to the Construction Division, $0,30 per board foot can be saved in shipping costs. If the Lumber Division has sufficient excess capacity to fulfill the Construction Division's needs, what will be the effect on the company's overall contribution margin? Decrease by $207000 Decrease by $30000 Increase by $31500 Increase by $33000