Critical Thinking Consider an x distribution with standard d

Critical Thinking Consider an x distribution with standard deviation sigma = 12. (a) If specifications for a research project require the standard error of the corresponding x distribution to be 2, how large does the sample size need to be? (b) If specifications for a research project require the standard error o the corresponding x distribution to be 1, how large does the sample size need to be?

Solution

a).

Standard error = s/sqrt(n)

s=12

se = 2 = 12/sqrt(n)

sqrt(n) = 12/2 =6

n=36

b)

se = 1 = 12/sqrt(n)

sqrt(n) = 12/1 =12

n=144