Problem Statement:
As the quality control engineer you are tasked to see if there is any difference between the product of four vendor (A, B, C, D). The ultimate tensile strength of 10 bolts has been experimentally measured. Perform an ANOVA analysis on the data at p=0.01 to determine if any statistical difference exist between vendors.
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Ultimate tensile strength (GPa)
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A
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B
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C
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D
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11
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13
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18
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11
|
|
13
|
14
|
16
|
12
|
|
17
|
16
|
18
|
16
|
|
17
|
19
|
20
|
15
|
|
15
|
20
|
22
|
14
|
|
16
|
18
|
15
|
17
|
|
14
|
16
|
17
|
13
|
|
10
|
17
|
21
|
16
|
|
12
|
15
|
18
|
17
|
|
14
|
18
|
20
|
18
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What is the null and alternative hypothesis?
Interpret the result of Tukey's HSD test.