math
posted by Aleah on .
In one year, the Dow Jones Industrial Average increased from 3,945 to 4,386. What percent increase does this represent to the nearest tenth of a percent?

And your answer is??

1%

How did you get that? I got a much different answer.

I divide 3945/4386=0.89, then I just rounded to 1%.

Ah  you forgot the subtraction part.
4,386  3,945 = 441
Now compare that difference with the original number.
441/3,945 = ?
We can prove an answer by reversing the procedure.
3,945 * 0.1 = 394.5
3,945 + 394.5 does not equal 4,386.