Question

Time spent using e-mail per session is normally distributed with a mean = to 8 minutes and standard deviation = 2minutes. If a random samples of 36 sessions were selected, the computed sample standard deviation would be
a. 0.25
b. 0.3333
c. 0.42
d. 0.48

Answer 1

Answer:

The correct option is (b) 0.3333.

Step-by-step explanation:

The standard deviation of the sampling distribution of sample mean $(\bar x)$ is known as the standard error $(\sigma_{\bar x})$.

The standard error is given as follows:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}$

The information provided is:

$\mu=8\\\\\sigma=2\\\\n=36$

Compute the standard deviation of the sample mean as follows:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}$

    $=\frac{2}{\sqrt{36}}\\\\=\frac{2}{6}\\\\=\frac{1}{3}\\\\=0.3333$

Thus, the standard deviation of the sample mean is 0.3333.