A Precision Control Engineer Is Interested in the Mean Length $\alpha$

question 107

Essay

A precision control engineer is interested in the mean length of tubing being cut automatically by machine.It is known that the standard deviation in the cutting length is 0.15 feet.A sample of 60 cut tubes yields a mean length of 12.15 feet.This sample will be used to obtain a 99% confidence interval for the mean length cut by machine.
a.What is the z $\alpha$ / 2 value to use in obtaining the confidence interval?
b.Develop the 99% confidence interval for $\mu$ .

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Definitions:

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a theory proposing four statuses of identity development: identity diffusion, foreclosure, moratorium, and achievement, based on the presence or absence of crisis and commitment.

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The practice of continuously asking questions to foster learning or find deeper understanding, often used in educational settings.

Status Offense

A noncriminal act that is considered a violation of the law only because of the offender's status as a minor, such as truancy or running away from home.

Truancy

The action of staying away from school without permission, often reflecting underlying issues such as family problems or disengagement.