The Forest Management Institute is conducting a test, which involves measuring the size of trees by ...

The Forest Management Institute is conducting a test, which involves measuring the size of trees by photographing from helicopter rather than actual field measurement. This process is especially important in forest areas accessible only by helicopter. A sample of 31 trees measured by aerial photography had a sample standard deviation of 2.24 . A 95 percent confidence interval for the population variance is represented by the values:
 a. 30(2.24) / 46.979 and 30(2.24) / 16.791.
  b. 30(2.242) / 46.979 and 30(2.242) / 16.791.
  c. 31(2.24) / 16.791 and 31(2.24) / 46.979.
  d. 31(2.242) / 46.979 and 31(2.242) / 16.791.
  e. 30(2.24) / 16.791 and 30(2.24) / 46.979.