1. DQO Training Course Day 3 Exercise 5 Hypothesis Testing for Clean & Dirty Sites Presenter: Sebastian Tindall (30 minutes)

2. Exercise 5 • For the first part of this Exercise, “Clean site”, the Action Level is still set at 7 ppm. • The LBGR is also still set to 6 ppm. • However, for this Exercise the True Mean for the “clean” bag of beads is 1 ppm. • The concentrations range from 0 to 4 ppm. • Therefore, “This site is Clean”.

3. Exercise 5 (contd.) • From the “clean” bag of beads, take a new random sample of n = 5 beads. • Provide your sample values to the instructor for spreadsheet calculations. • Your 95% UCL = • Check: Based on the UCL, your site is: “Clean”_____ or “Dirty” _____

4. Exercise 5 (contd.) • The current test is 95% UCL on x-bar >= AL implies “dirty,” otherwise site is “clean”. Record the number of sites that the class declared “dirty” below and calculate the error rate for the class: Number “dirty” Decisions --------------------------------- = ------------------------------ X 100 = Total Number of Decisions

5. Exercise 5 (contd.) • Draw in a green dot at 1 ppm on the x-axis of your DPGD at 0%.

6. Exercise 5 (contd.) • For the second part of this Exercise, “Dirty site”, the Action Level is still set at 7 ppm. • The LBGR is also still set to 6 ppm. • However, for this Exercise the True Mean for the “dirty” bag of beads is 13 ppm • The concentrations range from 10 to 14 ppm. • Therefore, “This site is Dirty”.

7. Exercise 5 (contd.) • From the “dirty” bag of beads, take a new random sample of n = 5 beads. • Provide your sample values to the instructor for spreadsheet calculations. • Your 95% UCL = • Check: Based on the UCL, your site is: “Clean”_____ or “Dirty” _____

8. Exercise 5 (contd.) • The current test is 95% UCL on x-bar >= AL implies “dirty,” otherwise site is “clean”. Record the number of sites that the class declared “clean” below and calculate the error rate for the class: Number “clean” Decisions --------------------------------- = ------------------------------ X 100 = Total Number of Decisions

9. Exercise 5 (contd.) • Draw in a black dot at 13 ppm on the x-axis line of your DPGD at 100%.

10. End of Exercise 5 Thank you Questions?