Question

If the sample size is nequals9​, what is the standard deviation of the population from which the sample was​ drawn?

Answer 1

Answer:

13.33

Step-by-step explanation:

As in the attached diagram,  we can see that the points belong to  $\mu\pm \sigma$ interval

Data provided in the question as per the details below:

$\mu_{\bar x}$ = 440

$\mu_{\bar x} + \sigma_{\bar x}$ = 480

So,

$\sigma_{\bar x}$ = 480 - 440

= 40

Now the standard deviation of the population is

$V(\bar{x}) = \frac{\sigma}{\sqrt n} \\\\ = \frac{40}{\sqrt 9}$

= 13.33

Hence, the standard deviation of the population for which the sample is drawn is 13.33