Question

For a population with a mean equal to 200 and a standard deviation equal to 25, calculate the standard error of the mean for the following sample sizes a) 20 b) 50 c) 80 a) The standard error of the mean for a sample size of 20 is (Round to two decimal places as needed.) b) The standard error of the mean for a sample size of 50 is (Round to two decimal places as needed.) c) The standard error of the mean for a sample size of 80 is (Round to two decimal places as needed.)

Answer 1

Solution :

Given that,

a) n = 20

The standard error is ,

$\sigma$_{$\bar x$} = $\sigma$ / $\sqrt$ n = 25 / $\sqrt$ 20 = 5.59

b)

n = 50

The standard error is ,

$\sigma$_{$\bar x$} = $\sigma$ / $\sqrt$ n = 25 / $\sqrt$ 50 = 3.54

c)

n = 80

The standard error is ,

$\sigma$_{$\bar x$} = $\sigma$ / $\sqrt$ n = 25 / $\sqrt$ 80 = 2.80