To provide information on whether coatings on iron pipes are of any use, 10 pieces of pipe are each marked off in equal segments, one to receive coating A, one to receive coating B, and the third left uncoated. For each pipe, the segment to receive A, for example, is decided upon by a suitable randomization scheme. The pipes then are chosen by selecting 1 specimen from each of 10 manufacturers. Once treated, the pipes are buried in soil for a year, removed, and the depths of the corrosion pits measured. The deepest pits so found are given below:
|
Coating
|
A
|
B
|
Untreated
|
|
Specimen
1
2
3
4
5
6
7
8
9
10
|
51
41
43
41
47
32
24
43
53
52
|
73
43
47
53
58
47
53
38
61
56
|
81
52
55
63
65
50
62
48
58
59
|
What type of experiment is this? Construct an ANOVA table, perform tests of significance, and comment. Use.