Answer:
Step-by-step explanation:
Given that:
The investment amount in account = $ 320
The rate of interest is = 8.1% compounded quarterly
Compunded quarterly means 8.1% / 4 = 0.02025
The time period = t years
The objective is to write a function showing the value of the account after t years.
From compound interest , compounded monthly.
[tex]Amount = Principal * ( 1 + \dfrac{rate}{12*100})^{12*time}[/tex]
[tex]= $320 *(1 + \dfrac{0.02025}{12*100})^{12t}[/tex]
[tex]= 320*(1+ 1.6875*10^{-5})^{12t}[/tex]
[tex]= 320 * ( 1.000016875)^{12t}[/tex]
Thus; the function after t years [tex]= $320 * ( 1.000016875)^{12t}[/tex]
The percentage of growth per year is :
= (1 + 0.02025)^4 - 1
= 1.083493758 - 1
= 0.083493758
= 8.4 % (APY) yearly
