Case Study 2: UFE Clubs Case Study, (10 marks)

UFE Clubs produces ball bearings. The diameter of the ball bearings is very important for the quality

purposes. The following tables shows the diameters of 17 randomly selected samples in

centimetres. Each sample contains four observations. Use control charts and run tests to see

whether or not the process is under control. For run test z = 1.

Sample Observation 1 Observation 2 Observation 3 Observation 4

1 31.22 24.01 31.75 22.49

2 31.67 32.43 29.78 27.54

3 27.83 25.37 26.49 25.83

4 31.48 28.02 30.21 31.86

5 28.27 30.99 28.62 25.46

6 28.23 24.44 32.56 32.41

7 24.58 26.89 27.11 32.36

8 28.16 29.47 22.32 30.78

9 28.21 29 32.88 24.69

10 32.15 29.18 24.84 31.29

11 23.91 24.65 29.29 22.32

12 23.20 29.23 29.31 26.36

13 23.54 31.11 31.81 26.56

14 30.64 26.94 29.23 32.29

15 31.87 32.48 24.56 25.51

16 29.33 23.36 23.36 25

17 27.02 23.05 31.19 28.44

Important note:

- For ALL calculation use Three decimal points

- Please note that for assignment 1 you need to submit just one file.

- Brief explanation is required on what you have done for each question.

- To calculate standard deviation,

Calculation for central tendency (Mean). Please

show graph. 2.5

b. Calculation for dispersion (R) Please show graph.

2.5

c. Run test calculation for median. 2.5

d. Run test calculation for Up and Down. 2.5