Use the Given Degree of Confidence and Sample Data to Find

question 156

Multiple Choice

Use the given degree of confidence and sample data to find a confidence interval for the population standard deviation σ.
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 10.9 years and the standard deviation is 2.7 years. Construct a 99% confidence interval for the standard deviation, σ, of the replacement Times of all washing machines of this type.

• A) \(1.9 \mathrm { yr } < \sigma < 5.7 \mathrm { yr }\)
• B) \(1.8 \mathrm { yr } < \sigma < 5.1 \mathrm { yr }\)
• C) \(2.0 \mathrm { yr } < \sigma < 4.3 \mathrm { yr }\)
• D) \(1.9 \mathrm { yr } < \sigma < 4.5 \mathrm { yr }\)

---

Definitions:

Healthier Environment

A setting or surrounding that promotes well-being and reduces the risk of health problems by minimizing pollutants, hazards, and stressors.

Early Adulthood

The period in a person's life typically ranging from the ages of 20 to 40, where many experience personal and professional growth.

Polygenetic

Involving or determined by multiple genes, often relating to the complex traits and variations in organisms.

DNA Segments

Portions of the DNA molecule that carry genetic information; these can encode genes, regulate gene expression, or have structural or unknown functions.