Question

Samples of size 25 are selected from a population with a mean of 40 and a standard deviation of 7.5 what is the mean of error of the sampling distribution of sample means

Answer 1

Given: $n=25, \mu=40, \sigma=7.5$

$E(\=x)=\mu=40$ , because the mean of the sampling distribution of the sample mean is equal to the population mean.

Standard deviation of the sampling distribution:

$\sigma_{\=x}=\frac{\sigma}{\sqrt{n}}=\frac{7.5}{5}=1.5$