Chapter 7.5, Problem 10P

Critical Thinking Consider an x distribution with standard deviation $\sigma =12$. (a) If specifications for a research project require the standard error of the corresponding $\bar{x}$ distribution to be 2, how large does the sample size need to be?

(b) If specifications for a research project require the standard error of the corresponding $\bar{x}$ distribution to be 1, how large does the sample size need to be?