Answer:
410.32
Step-by-step explanation:
Given that the initial quantity, Q= 6200
Decay rate, r = 5.5% per month
So, the value of quantity after 1 month, [tex]q_1 = Q- r \times Q[/tex]
[tex]q_1 = Q(1-r)\cdots(i)[/tex]
The value of quantity after 2 months, [tex]q_2 = q_1- r \times q_1[/tex]
[tex]q_2 = q_1(1-r)[/tex]
From equation (i)
[tex]q_2=Q(1-r)(1-r) \\\\q_2=Q(1-r)^2\cdots(ii)[/tex]
The value of quantity after 3 months, [tex]q_3 = q_2- r \times q_2[/tex]
[tex]q_3 = q_2(1-r)[/tex]
From equation (ii)
[tex]q_3=Q(1-r)^2(1-r)[/tex]
[tex]q_3=Q(1-r)^3[/tex]
Similarly, the value of quantity after n months,
[tex]q_n= Q(1- r)^n[/tex]
As 4 years = 48 months, so puttion n=48 to get the value of quantity after 4 years, we have,
[tex]q_{48}=Q(1-r)^{48}[/tex]
Putting Q=6200 and r=5.5%=0.055, we have
[tex]q_{48}=6200(1-0.055)^{48} \\\\q_{48}=410.32[/tex]
Hence, the value of quantity after 4 years is 410.32.
