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The answer to this is: the upper bound for the length is Lower and Upper Bounds
The lower bound is the smallest value that will round up to the approximate value.
The upper bound is the smallest value that will round up to the next approximate value.
Ex:- a mass of 70 kg, rounded to the nearest 10 kg, The upper bound is 75 kg, because 75 kg is the smallest mass that would round up to 80kg.
Here , A length is measured as 21cm correct to 2 significant figures. We need to find what is the upper bound for the length . let's find out:
As discussed above , upper bound for any number will be the smallest value in decimals which will round up to next integer value . So , for 21 :
⇒
21.5 cm on rounding off will give 22 cm . So , the upper bound for the length is
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