英语翻译By using a new process the prime cost of the television set was reduced by 3.4 times.为什么was reduced by 3.4 times 是翻译成“降低了71% ” ,也就是12/17?The sales of TV set have risen 3.5 fold.为什么risen 3.5 fold 是翻

英语翻译By using a new process the prime cost of the television set was reduced by 3.4 times.为什么was reduced by 3.4 times 是翻译成“降低了71% ” ,也就是12/17?The sales of TV set have risen 3.5 fold.为什么risen 3.5 fold 是翻
英语翻译
By using a new process the prime cost of the television set was reduced by 3.4 times.
为什么was reduced by 3.4 times 是翻译成“降低了71% ” ,也就是12/17?
The sales of TV set have risen 3.5 fold.
为什么risen 3.5 fold 是翻译成“增加了2倍半”.
我不是讲英文翻译，翻译我懂，就是3.4怎么变成12/17的？3.5怎么变成两倍半？这个我没搞懂。

英语翻译By using a new process the prime cost of the television set was reduced by 3.4 times.为什么was reduced by 3.4 times 是翻译成“降低了71% ” ,也就是12/17?The sales of TV set have risen 3.5 fold.为什么risen 3.5 fold 是翻
由倍数换算成分数表示减少后的结果,译成“减少到几分之一”或“减少为几分之一”.例如,
reduce by 3 times 减少到1/3 或减少了2/3
reduce by 5 times 减少到1/5 或减少了4/5
reduce by 10 times 减少到1/10 或减少了9/10
reduced by 3.4 times即减少到 1/3.4,算成整数分母,即“降低到5/17”或“降低了12/17”,但这样仍不符合汉语习惯.在不要求绝对精确的情况下,可进一步换算成百分数,即“降低到29%”或“降低了71%”.

答：1）reduced by +倍数，翻译为降低了……倍数
2）reduced to+小数， 翻译为降低到……
所以，第一个应该翻译为“降低了3.4倍”
3）raise为及物动词直接可以接倍数，翻译为增加了多少倍
4）rise为不及物动词，用法与reduce相同。

是这样的，原来有一个基数，无论是reduce, 还是rise，后面by是指增加到多少，而不是增加了，注意增加到多少，增加了多少是不一样的。
比如：原来有5斤，增加到7斤，只增加了2斤，现在还是7斤；
而增加了7斤则现在有14斤。
谢谢采纳！