environ-samplinganalysis-analyzing-lab-results
In the table below are the results from four analytical labs, each of which analyzed the same soil sample for its benzene content. The actual concentration of benzene in the soil is 25 ppb.
| Reported Concentration of Benzene in a Soil Sample (ppb) | ||||
| Replicate | Lab A | Lab B | Lab C | Lab D |
| 1 | 25 | 19 | 25 | 28 |
| 2 | 29 | 29 | 25 | 27 |
| 3 | 21 | 30 | 27 | 27 |
| 4 | 23 | 16 | 25 | 29 |
| 5 | 27 | 16 | 25 | 29 |
| 6 | 22 | 21 | 24 | 27 |
| 7 | 27 | 16 | 28 | 26 |
| 8 | 20 | 29 | 26 | 27 |
| 9 | 30 | 26 | 25 | 28 |
| 10 | 25 | 30 | 27 | 27 |
- Compare the four sets of data:
- Which lab do you think has the most accurate data?
- Which lab has the most precise data?
- Is it the same lab?
- Using the formulas for average error and variance found in the Critical Thinking: Comparing Accuracy and Precision of Four Different Labs Lesson, calculate the accuracy and precision of each lab’s data.
- Was your initial evaluation correct regarding which lab generated the most accurate and most precise data? Show your work.
