CHAPTER 1

INTRODUCTION TO DATA ANALYSIS

1-2.

One possibility is in Figure 1:

 

Figure 1:   Stratified plot, Exercise 1-2

1-4.

No data are needed. Ideas about what affects the phenomenon under study are needed.

1-6.

The process is not stationary. Plot of URATE versus DATE shows this.

1-7.

 

Scale 1 2 3 4 5 6 7 8 9 10

Worn Gears x x x x

Mis-calibration x x x x x x x

1-9.

a.

Not stationary. There is a big drop in 1896. Plot of times versus year.

b.

A downward trend in times even after 1896.

1-15.

1-16.

Month 1 2 3 4 5 6

Moving Average 5 6 7.5 7 7.5 10.5

1-26.

a.

R&R:repeatability and reproducibility.
Repeatability measures the consistency of the scale in repeated measurements of this weight by the same operator.
Reproducibility measures the variation between different operators.

b.

Stationarity must be checked. Plot each operator's measurements versus time.

c.

Operator 2 has a much larger repeatability problem than either operator 1 or operator 3. Operator 2 should be worked with to identify and eliminate this problem.