A Simple Random Sample of Kitchen Toasters Is to Be $\sigma = 20$

question 90

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 $\sigma = 20$ hours.
Find the sample size needed so that a $98 \%$ confidence interval for the mean lifetime will have a margin of error of 8 .

• A) 117
• B) 5
• C) 6
• D) 34

---

Definitions:

Multinational Corporations

Large companies that operate in multiple countries, managing production or delivering services in more than one country outside of their home base.

Recombinant DNA

DNA molecules formed by laboratory methods of genetic recombination to bring together genetic material from multiple sources.

Diesel-electric Hybrid

A vehicle that uses a diesel engine combined with an electric motor to drive, aiming to achieve greater fuel efficiency and lower emissions than traditional diesel engines.

Green Revolution

A set of research, development, and technology transfer initiatives, taking place between the 1940s and the late 1960s, that increased agriculture production worldwide, particularly in developing countries.