8 times the income is gained by families now than fifty years ago on average

问题描述:

8 times the income is gained by families now than fifty years ago on average

语法是对的

对的,现在家庭的平均收入是五十年前的八倍。

the income gained by families now is 8 times than fifty years ago on average

易产生歧义不如改成这样
8 times the income gained now is than the one fifty years ago on average.

Incomes gained by family now on average is 8 times the income fifty years ago.
中文解作:现在的家庭收入平均是五十年前的八倍.