Answer: 0.10%
Explanation:
The following can be gotten from the question:
n = 15 years
We change it to months. Thus will be:
= 15 × 12
= 180
Present value of an annuity :
= A × {1- (1 +r ) -n ]/r}
74000 = 450 × [ 1- (1 +r) - 180]/r
r= 0.10%
Therefore, the monthly interest rate is 0.10%.