Answer:
1.8356 years
Explanation:
The computation of the purchase of maturity bond is shown below:
Years (A) Payment PVF at 9% PV Weight (B) Duration (A × B)
1 $8,000,000 0.9174 $7,339,449.54 0.7215 0.7215
4 $4,000,000 0.7084 $2,833,700.84 0.2785 1.1142
$101,731,503.39 1 1.8356