The Douglas County School District sold $9 million of bonds on Nov. 28 to fund improvements and upgrades to existing school buildings. Bids, which were received from four national underwriting firms, ranged from 2.9 percent to 3.4 percent. Piper Jaffray submitted the best bid with an overall interest rate of 2.9 percent.“We are thrilled with the fantastic interest rate we received,” said Superintendent Lisa Noonan. “This bond sale will allow us to get started on the first phase of the Douglas High School Master Plan.”The district’s bonds were rated AA- by Standard & Poor’s, which is among the highest rating …