Choose the One Alternative That Best Completes the Statement or Answers

Multiple Choice

Choose the one alternative that best completes the statement or answers the question.
-A random sample of 40 part-time workers has a mean annual earnings of $\$ 3120$ and a population standard deviation of $\$ 677$ . Compute the $95 \%$ confidence interval for $\mu$ .

A) $( \$ 2910 , \$ 3330 )$
B) $( \$ 210 , \$ 110 )$
C) $( \$ 4812 , \$ 5342 )$
D) $( \$ 1987 , \$ 2346 )$