I was solving some mathematical questions and have come across the situation, where I need to divide 3900/139. Here is my question,
a. Can I assume 139 to 140 for the ease of division?
If so, how will I know what percentage of error I am introducing? How can I ensure that I am adding very less value to a number and the results will not be tremendously affected?
Best Answer
N/139 = real answer
N/140 = your answer
your answer/real answer = (N/140)/(N/139) = 139/140.
Your answer will be 1/140 too small.
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in general if you replace p with (p + n) your result will by factor of n/(p+n)
Replace 487 with 500 and your be off by a factor of 13/500.
Basically your answer will be off be the same proportion as your rounding was off.