Self-test 3.6 – Estimation of measurement uncertainty in chemical analysis

1. Please calculate the half-width of the confidence interval at 95% probability for the arithmetic mean of copper concentrations found in a drinking water sample (all in mg/l). The results of Cu content in drinking water are: 0.276, 0.329, 0.242, 0.321, 0.267 mg/l.

2. A graph with distribution functions is given. Which line corresponds to which distribution function? Please choose the respective color.

Which line corresponds to which distribution function:

a) Rectangular distribution

b) Triangular distribution

c) Normal distribution

d) Student distribution

3. Question 3 text and clues
Please calculate the confidence interval at 95% probability for the arithmetic mean of copper concentrations found in a drinking water sample (all in mg/l). The results of Cu content in drinking water are: 0.276, 0.329, 0.242, 0.321, 0.267 mg/l.

4. Question 3 a

Please present here the lower limit of the 95% confidence interval with the same number of significant digits that is the initial data.

5. Question 3 b

Please present here the upper limit of the 95% confidence interval with the same number of significant digits that is the initial data.

6. Cu content in drinking water was determined and the results are:

C_Cu (mg/l)

0.276

0.329

0.242

0.321

0.267

Please calculate the half-width of the confidence interval at 95% probability for the arithmetic mean of copper concentrations found in a drinking water sample. Please give the answer with 2 significant digits and don't forget correct unit!

Please calculate the confidence interval at 95% probability for the arithmetic mean of copper concentrations found in a drinking water sample.

A. Please present here the lower limit of the 95% confidence interval with the same number of significant digits that is the initial data.

B. Please present here the higher limit of the 95% confidence interval with the same number of significant digits that is the initial data.

Here are some clues!