Question

The mass of potassium in a one-cup serving of this cereal is determined to be 172 mg. Show a numerical setup for calculating the percent error for the mass of potassium in this serving.?

Answer 1

Answer:

$Absolute = |172-170|= 2mg$

$\Relative_{error}= \frac{|172-170|}{170}*100 =\frac{2}{170} *100=1.176 \%$

Explanation:

Assuming this complete problem: "Potassium phosphate, K3PO4, is a source of dietary potassium found in a popular cereal. According to the Nutrition-Facts label shown on the boxes of this brand of cereal, the accepted value for a one-cup serving of this cereal is 170. milligrams of potassium. The minimum daily requirement of potassium is 3500 milligrams for an adult human.

The mass of potassium in a one-cup serving of this cereal is determined to be 172 mg. Show a numerical setup for calculating the percent error for the mass of potassium in this serving.?"

Solution to the problem

For this case we can use the absolute error given by:

$Absolute = |Estimated-Real|$

Or the relative error given by:

$\% Relative_{error}= \frac{|Estimated-Real|}{Real} *100$

For this case we know that the accepted value for a one-cup serving of this cereal is 170 milligrams (Real value) of potassium and for the specific case on the experiment the estimated value in a one cup serving of this ceral is determined 172mg that represent the measured value.

So we can replace and we got:

$Absolute = |172-170|= 2mg$

$\Relative_{error}= \frac{|172-170|}{170}*100 =\frac{2}{170} *100=1.176 \%$