Question

The Average adult weight of a particular breed of dog is 45 pounds with a Standard deviation of 7.2 pounds. If random samples of 30 dogs were taken of this breed, which of the following is closest to the standard deviation of their sample mean?1. 0.922. 1.313. 1.494. 1.85

Answer 1

The question is asking for the number closest to the standard deviation.

We can find this by calculating the Standard Error (SE) of the sample size:

$SE=\frac{\sigma}{\sqrt[]{n}}$

where

$\begin{gathered} \sigma=S\tan dard\text{ Deviation = 7.2} \\ n=\text{sample size = 30} \end{gathered}$

Substituting, we have the Standard Error as

$\begin{gathered} SE=\frac{7.2}{\sqrt[]{30}} \\ SE=1.31 \end{gathered}$

Hence, OPTION 2 is correct.