:5. Solution.  Since the size of the sample is small in
comparison with the size of the population being sampled, we
proceed as if the sampling were without replacement.  The sample
average is 10,000/100 = 100.  Estimating the box SD by the sample
SD, we obtain <p>

SE for the sum = 20 x (100)^(1/2) = 20 x 10 = 200  <p>

SE for the average = 200/100 = 2  <p>

95% confidence interval = 200 +/ (2x2) = 200 +/  4  <p>