The reasons of gross sales margin higher than expected one are as following.
Product series
Changed the packing material, Purchase price changed for the raw material.
The unit price of material A reduced.
The production plan changed, 3 raw materials cancelled
the cost of transportation between processes are not calculated into the total cost.
The unit selling price was not changed according to the above.
Please forgive me for the mistake. The errors in the data filling have been corrected.