Question

When testing a hypothesis about a single mean, if the sample size is 51 and the population standard deviation is known, the correct test statistic to use is ___________.

Answer 1

Answer:

z-statistic

Step-by-step explanation:

We have to identify the correct test statistic to use with the given conditions.

• If the sample size is larger than 30, then the sample is considered to be large.
• We are given a sample size of 51, which is a a large sample.
• Also, the population standard deviation is known.
• Thus, we use the z-statistic when testing a hypothesis about a single mean.
• Formula:

$z_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{\sigma}{\sqrt{n}} }$

where $\bar{x}$ is the sample mean, $\mu$ is the population mean, $\sigma$ is the population standard deviation and n is the sample size.