Answer:
a. $965.74 
b. $939.11 
Step-by-step explanation:
In this question we use the Present value formula i.e shown in the attachment below:
1. Given that, 
Future value = $1,000 
Rate of interest = 6.5% 
NPER = 4 years 
PMT = $1,000 × 5.5% = $55
The formula is shown below: 
= -PV(Rate;NPER;PMT;FV;type) 
So, after solving this, the price would be $965.74 
2. Given that, 
Future value = $1,000 
Rate of interest = 6.5% 
NPER = 8 years 
PMT = $1,000 × 5.5% = $55
The formula is shown below: 
= -PV(Rate;NPER;PMT;FV;type) 
So, after solving this, the price would be $939.11