In hypothesis testing for a population mean, which symbol typically represents the test statistic used to evaluate the null hypothesis?

• A. $z$
• B. $p$
• C. $\mu$
• D. $\alpha$

Answer: (A)

Verified step by step guidance

1. Understand that in hypothesis testing for a population mean, the test statistic is a standardized value used to decide whether to reject the null hypothesis.
2. Recall the common symbols used in hypothesis testing: \(\mu\) represents the population mean, \(\alpha\) is the significance level, \(p\) is the p-value, and \(z\) is the test statistic when the population standard deviation is known or the sample size is large.
3. Recognize that the test statistic compares the sample mean to the hypothesized population mean, standardized by the standard error.
4. The formula for the test statistic \(z\) in this context is: \(z = \frac{\bar{x} - \mu_0}{\sigma / \sqrt{n}}\) where \(\bar{x}\) is the sample mean, \(\mu_0\) is the hypothesized population mean, \(\sigma\) is the population standard deviation, and \(n\) is the sample size.
5. Therefore, the symbol \(z\) typically represents the test statistic used to evaluate the null hypothesis in hypothesis testing for a population mean.