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The Tough Twine Company claims that their twine has an average breaking strength of 16.5 pounds....

The Tough Twine Company claims that their twine has an average breaking strength of 16.5 pounds. The head of the shipping department at Korber’s hardware store suspects that this figure is too high and wishes to test the appropriate hypothesis. He takes a random sample of 36 pieces and finds that the mean breaking strength of the sample is 15.8 lbs with s = 2.9 lbs.

(a) State the null hypothesis and alternative hypothesis

(b) Find the test statistic

(c) If the type-I error α = 0.05, find the critical value(s) and shade the rejection region(s)

(d) Base on the type-I error α and rejection region(s), given above, what is your conclusion?

Math   Statistics-And-Probability   
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Answer #1

a)

The Tough Twine Company claims that their twine has an average breaking strength of 16.5 pounds.

The head of the shipping department at Korber’s hardware store suspects that this figure is too high.

u : twine has an average breaking strength of fewer than 16.5 pounds.

Ho:- u = 16.5

vs

Ha:- u < 16.5

b)

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