A Simple Random Sample of Kitchen Toasters Is to Be $\sigma = 21$

question 45

Multiple Choice

A simple random sample of kitchen toasters is to be taken to determine the mean operational lifetime in hours. Assume that the lifetimes are normally distributed with population standard Deviation $\sigma = 21$ hours.
Find the sample size needed so that a 98% confidence interval for the mean lifetime will have a margin Of error of 4.

• A) 13
• B) 150
• C) 3
• D) 257

---

Definitions:

Tensions

Psychological or emotional strain or stress that can arise from a variety of sources, often associated with conflicting demands or challenges.

Realistic Conflict Theory

A social psychological model that explains how conflict and hostility between groups arise from competition over resources or conflicting goals.

Competition

A situation in which individuals or groups vie with each other to achieve a goal that cannot be shared or that is desired individually.

Perceptions

The process of interpreting, organizing, and giving meaning to the sensory information we receive from the environment.