A random sample of 100 bars of aluminum shows a tensile strength mean of 30,000 psi and a standard deviation of 3,000 psi. On the basis of this sample, what is the 95 percent confidence interval for…

The correct answer is C. 30,000 ?588 psi. See the full explanation below for the reasoning.

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Question

A random sample of 100 bars of aluminum shows a tensile strength mean of 30,000 psi and a standard deviation of 3,000 psi. On the basis of this sample, what is the 95 percent confidence interval for the average tensile strength?

Options

A30,000 ?528 psi
B30,000 ?600 psi
C30,000 ?588 psi
D30,000 ?768 psi

How the community answered

(61 responses)

A
3% (2)
B
11% (7)
C
77% (47)
D
8% (5)

Topics

#confidence interval#statistical inference#sampling#standard deviation

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