Use the Given Degree of Confidence and Sample Data to Find

question 37

Multiple Choice

Use the given degree of confidence and sample data to find a confidence interval for the population standard deviation ?.
Assume that the population has a normal distribution. Round the confidence interval limits to the same number of decimal places as the sample standard deviation.
-The mean replacement time for a random sample of 20 washing machines is 9.4 years and the standard deviation is 2.5 years. Construct a 99% confidence interval for the standard deviation, ?, of the replacement times of all washing machines of this type.

• A) \(1.8 \mathrm { yr } < \sigma < 4.2 \mathrm { yr }\)
• B) \(1.8 \mathrm { yr } < \sigma < 3.9 \mathrm { yr }\)
• C) \(1.7 \mathrm { yr } < \sigma < 4.8 \mathrm { yr }\)
• D) \(1.8 \mathrm { yr } < \sigma < 5.3 \mathrm { yr }\)

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Definitions:

Emotional Stability

A personality trait characterized by the ability to remain calm and composed, particularly in stressful or challenging situations.

Value

The importance, worth, or usefulness of something, often considered in terms of financial, cultural, or personal significance.

Applicants

Individuals or candidates who apply for a job, program, or opportunity.

Locus Of Control

A psychological concept that categorizes individuals based on their belief in personal control over life events, either internally (control lies within oneself) or externally (control lies outside).