Calculation Steps

The last full week in November 2010 was November 15-19.

The yields on one-year United States Treasury securities adjusted for constant maturity for this week are:

Monday, November 15
 0.29%
 
Tuesday, November 16
 0.27%
 
Wednesday, November 17
 0.26%
 
Thursday, November 18
 0.26%
 
Friday, November 19
 0.27% 
 

These yield rates come from the U.S Department of the Treasury's Interest Rate Statistics, specifically the one-year Daily Treasury Yield Curve Rates from Treasury's web site.

The average of these five yields is 0.27%. The required interest rate, rounded to the nearest tenth of a percent, is 0.3%.