To help decide which of your two current suppliers deserves the larger contract next year, you have rated a random sample of plastic cases from each one. The data are a composite of several measurements, with higher numbers indicating higher quality. (Table 10.7.11)
1. Find the two-sided 95% confidence interval for the quality difference. Is there a significant difference in quality? How do you know?
|
Custom Cases Corp
|
International Plastics
|
|
54.3
|
93.6
|
|
58.8
|
69.7
|
|
77.8
|
87.7
|
|
81.1
|
96.0
|
|
54.2
|
82.2
|
|
78.3
|
|