Question

A simple random sample of 64 observations was taken from a large population. The sample mean and the standard deviation were determined to be 320 and 120 respectively. The standard error of the mean is:________

a. 1.875
b. 40
c. 5
d. 15
e. None of the above

Answer 1

Answer:

The correct option is d

Step-by-step explanation:

From the question we are told that

    The sample size is  n = 64

    The mean is  $\= x = 320$

    The standard deviation is $\sigma = 120$

Generally the standard error of the mean is mathematically represented as  

       $\sigma_x = \frac{\sigma}{ \sqrt{n} }$

=>    $\sigma_x = \frac{120}{ \sqrt{64} }$

=>    $\sigma_x =15$