Question

Reserve Problems Chapter 9 Section 2 Problem 7 An engineer who is studying the tensile strength of a steel alloy intended for use in golf dub shafts knows that tensle strength is approximately normally d tributed th σ-60 si A random sample of 12 specimens has a mean tensile strength of X 3450 psi. (a) If the mean strength is 3500 psi, what is the smallest level of significance at which you would be willing to reject the null hypothesis? Use a-0.01 Round your answer to four decimal places (e.g. 98.7654). The smallest level of sigrificance (b) what is the B-error if the true mean is 3470 and α-. 0.017 Round your answer to three decimal places (e.g. 98.765) (c) Suppose that you wanted to reject the null hypothesis with probability at least 0.8 if mean strength μ-3470 pst what sample s ze should be used?

Answer 1

the p value is the smallest level of significance where you are willing to reject the null

Right-tailed p-value: P(Z > z) = 0.2023378
-6 5 3 2-1 023 4 5 67 The p-value is the area to the right of z

beta or type 2 error is 0.0026