91Ó°ÊÓ

The values are

The sample mean's sampling distribution mean is equal.

${\mathrm{μ}}_x=\mathrm{μ}=40.125$

The sample as the units of the population mean are the units of the mean of the sampling distribution of the sample mean, and so the mean is $40.125\mathrm{mm}$

The values are,

$$\begin{gathered} \mathrm{μ}=40.125 \\ \mathrm{σ}=0.002 \\ n=4 \end{gathered}$$

Let use the following formula

${\mathrm{σ}}_{\stackrel{¯}{x}}=\frac{\mathrm{σ}}{\sqrt{n}}$

The sample mean is the mean of the sampling distribution.

${\mathrm{μ}}_{\stackrel{¯}{x}}=\mathrm{μ}=40.125$

The standard deviation of the sample mean's sampling distribution is

${\mathrm{σ}}_x=\frac{\mathrm{σ}}{\sqrt{n}}=\frac{0.002}{\sqrt{4}}=\frac{0.002}{2}=0.001$

The units of the sampling distribution's standard deviation of the sample mean are the same as the units of the population standard deviation, so the standard deviation is $0.001\mathrm{mm}$.

In an hour, the sample mean diameter of four randomly selected axles fluctuates by an average of $0.001\mathrm{mm}$from the mean diameter of $40.125$