[译] 由于使用新工序，原材料的损耗下降了4/5。
[误] By using the new process, the loss of raw and processed materials is reduced by a factor of 4/5.

[正] By using the new process, the loss of raw and processed materials is reduced by a factor of 5.
[注] reduce (decrease, shorten) by a factor of + n times 汉语用分数表示，而英语须用整数，又如: The new equipment will decrease the error probability by a factor of 6. 新设备将使误差率降低5/6。