问题详情

If it were discovered that the import dollar amount shown for 1978 was incorrect and should have been $ 5. 3 billion instead, then the average (arithmetic mean) import dollar amount per year for the 17 years would be how much less？
A．$100 million
B．$53 million
C．$47 million
D．$17 million
E．$7 million请帮忙给出正确答案和分析，谢谢！