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An engineer who is studying the tensile strength of a steel alloy knows that the population...

An engineer who is studying the tensile strength of a steel alloy knows that the population of tensile strength is approximately normally distributed with s = 60 psi. He selected a random sample of 12 specimens and gave a mean tensile strength of 3450 psi

. (i) Test the hypothesis that mean strength is 3500 psi. Use α = 0.05.

(ii) What is the P-value for the test in (i)?

(iii) Explain how you could answer the question in part (i) by using a confidence interval?

Math   Statistics-And-Probability   
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