Please fill in a number in both boxes (last row of the table above)

Correct

You are not right, try to correct your answer. Maybe it is most easy to calculate the CV in steps. (1) Calculate the logarithm of the concentration (2) Multiply this by 0.5 and so on. Remember that the C in the equation represent a fraction, so 37.779 g fat /100 g equals C=0.3777

Not right, now the right answers are shown in the table.

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Here you find the results of an interlaboratory trial in which the fat contents of several products is determined by different labs. This will provide you with an insight in the quality of total fat analysis. Study the results and answer the questions.

To know whether the fat measurements are sufficiently precise you have to know which CV between is reasonably achievable. This can be calculated using the 'Horwitz equation'. C is the concentration of the component that was measured (here total fat). C has to be expressed as a fraction (e.g. 37.779 g/100g = 0.37779g/g).

Calculate the achievable CV between for all six foods using this equation. Add the results to the table above.