SOLUTION STEPS:
  1. Write the number with place-value labels: 3=tens, 0=ones, 7=tenths, 9=?, 4=thousandths.
  2. Count the decimal places: 1st decimal = tenths, 2nd = hundredths, 3rd = thousandths.
  3. The digit 9 is in the 2nd decimal place, which is hundredths.