a sample of ten vouchers is randomly selected without replacement from 6000 vouchers. If 10% of the population of vouchers contain errors the standard deviation of x is

Answer 1

If x is the number of errors in the sample, sd(x) = sqrt(n(p)(1-p))sqrt((N-n)/(N-1))

The second sqrt is the finite sample correction factor.

sqrt(10(.1)(.9))sqrt((6000-10)/(6000-1)) =