Probability and Statistics for Engineering and the Sciences
9th Edition
ISBN: 9781305251809
Author: Jay L. Devore
Publisher: Cengage Learning
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Chapter 6.2, Problem 25E
The shear strength of each of ten test spot welds is determined, yielding the following data (psi):
- a. Assuming that shear strength is
normally distributed , estimate the true average shear strength and standard deviation of shear strength using the method of maximum likelihood. - b. Again assuming a normal distribution, estimate the strength value below which 95% of all welds will have their strengths. [Hint: What is the 95th percentile in terms of μ and σ? Now use the invariance principle.]
- c. Suppose we decide to examine another test spot weld. Let X = shear strength of the weld. Use the given data to obtain the mle of P(X ≤ 400). [Hint: P(X ≤ 400) = Φ((400 − μ)/σ).]
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Chapter 6 Solutions
Probability and Statistics for Engineering and the Sciences
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