The Treasury Department said yields on three-month bills dropped to 8.48%, down from 8.73% the week before. Rates on six-month bills dropped to 8.79%, down from 8.98%. The Treasury sales totaled $14 billion of new securities--half in three-month bills and half in six-month bills. The new discount rates understate the actual return to investors--8.79% for three-month bills and 9.33% for six-month bills. The discount rate reflects the price discount received when government securities are purchased at less than face value.