Chapter 13, Problem 13.91ACI

New iron-making process. Mining Engineering (October 2004) published a study of a new technology for producing carbon high-quality iron nuggets directly from raw iron ore and coal. For one phase of the study, the percentage change in the carbon content of the produced nuggets was measured at 4-hour intervals for 33 consecutive intervals. The data for the 33 time intervals are listed in the table below. Specifications state that the carbon content should be within 3.42 ± 0.3 percent.

Interval		Carbon Change(%)
1		3.25
2		3.30
3		3.23
4		3.00
5		3.51
6		3.60
7		3.65
8		3.50
9		3.40
10		3.35
11		3.48
12		3.50
13		3.25
14		3.60
15		3.55
16		3.60
17		2.90
18	3.55
19	3.48
20	3.42
21	3.40
22	3.50
23	3.45
24	3.75
25	3.52
26	3.10
27	3.25
28	3.78
29	3.70
30	3.50
31	3.40
32	3.45
33	3.30

Source: G. Hoffman and O. Tsuge, “Tmk3–Application of a New Ironmaking Technology for the Iron Ore Mining Industry,“ Mining Engineering, Vol. 56, No. 9,2004. Copyright © 2004 by the Society for Mining. Metallurg. & Exploration. Used by permission of Society for Mining. Metallurg & Exploration.

1. a. Construct a capability analysis diagram for the iron-making process.
2. b. Determine the proportion of carbon measurements that fall outside specifications.
3. c. Find the capability index for the process and interpret its value.