# Question: To help you decide which of your two current suppliers

To help you 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).

a. Find the average quality for each supplier.

b. Find the standard deviation of quality for each supplier.

c. Find the average difference in quality (International minus Custom) and its standard error.

d. Find the two-sided 95% confidence interval for the quality difference.

e. Is there a significant difference in quality? How do you know?

a. Find the average quality for each supplier.

b. Find the standard deviation of quality for each supplier.

c. Find the average difference in quality (International minus Custom) and its standard error.

d. Find the two-sided 95% confidence interval for the quality difference.

e. Is there a significant difference in quality? How do you know?

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