Answer: d. 1.3333
Step-by-step explanation:
We know that the standard error of a sampling distribution is given by :-
[tex]S.E.=\dfrac{\sigma}{\sqrt{n}}[/tex]
, where [tex]\sigma[/tex] = Population standard deviation.
n= Sample size.
AS per given , we have
[tex]\sigma =12[/tex]
n=81
Then, the standard error of a sampling distribution with a population standard deviation of 12 and the sample size of 81 will be :-
[tex]S.E.=\dfrac{12}{\sqrt{81}}[/tex]
[tex]=\dfrac{12}{\sqrt{9^2}}=\dfrac{12}{9}\\\\=\dfrac{4}{3}\\\\\approx1.3333[/tex]
Hence, the standard error of a sampling distribution with a population standard deviation of 12 and the sample size of 81 is 1.3333.
Thus the correct answer is d. 1.3333 .
