explain why the variability in a parent population is greate

explain why the variability in a parent population is greater that that if a sampling distribution for sample sizes of size 10 from the same distribution

Solution

because sampling distribution of sample mean has mean of mu (same as population) but variance of sigma^2 / n

where n is sample size, which is 10 here. Thus the variance of sampling distribution is 1/10th of that of population.