In the Formula $\bar { x } \pm z _ { \alpha / 2 } \sigma / \sqrt { n }$

Short Answer

In the formula $\bar { x } \pm z _ { \alpha / 2 } \sigma / \sqrt { n }$ , the $\alpha / 2$ refers to: $\begin{array}{|l|l|}\hline A&\text {the probability that the confidence interval will contain the populati on mean. }\\\hline B&\text { the probability that the confidence interval will not contain the population mean. }\\\hline C&\text {the area in the lower tail or upper tail of the sampling distribution of the sample mean. }\\\hline D&\text { the level of confidence.}\\\hline \end{array}$