Answer:
I have to invest $11364.
Step-by-step explanation:
The formula of Compound Interest is:

where A = Amount
P = Principle
r = rate
n = Number of Compounding per year
t = total number of year
Here, A = 15000, r = 5.75% = 0.0575, n = 4(quarterly), and t = 5.
Putting all these values in above formula:

⇒

⇒

⇒

⇒ P = 11364
Hence, I have to invest $11364 for 5 years.