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# Z test for proportion

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Factories are being compared to see if there is a difference in the average defect rates of the chips they produce. In the first factory 250 chips are sampled, In the 2nd factory 350 chips are sampled. Proportions of defective chips are 4.0% and 6.0% respectively. Using a confidence level of 95%. Which statement is supported by data?

A) 1st factory average defect rate is lower than the 2nd on 95 out of 100 days. B) Not sufficient evidence to show a significant difference in average defect rate of 2 factories. C) There is a significant difference in average defect rate of 2 factories.D) None of the above

https://brainmass.com/statistics/hypothesis-testing/statistical-hypothesis-testing-z-test-proportion-138341

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Factories are being compared to see if there is a difference in the average defect rates of the chips they produce. In the first factory 250 chips are sampled, In the 2nd factory 350 chips are sampled. Proportions of defective chips are 4.0% and 6.0% respectively. Using a confidence level of 95%. Which statement is supported by data?

A) 1st factory average defect rate is lower than the 2nd on 95 out of 100 days.
B) Not sufficient ...

#### Solution Summary

Step by step method for computing test statistic for Z test for proportion is given in the answer.

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