=+39. Historical interest rates. Here’s a plot showing the federal rate on 3-month Treasury bills from 1950 to 1980, and a regression model fit to the relationship between the Rate

(in %) and Years since 1950. (www.gpoaccess.gov/eop/)

3 6

9 12 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Rate (%)

Years since 1950 Dependent variable is: Rate R-squared = 77.4% s = 1.239 Variable Coeff Intercept 0.640282 Year-1950 0.247637