Respuesta :
Answer:
initial principal amount is $ 28272.36
after 7 year interest rate = 0.4514 %
amount after 8 year is = $63489.85
Explanation:
given data
amount = $54000 for 6 year i.e 72 months
amount = $67000 for 8 year i.e 96 months
to find out
How much money does he have now and after 7 years, the nominal rate halves and then stays at that value, how much money will he have in 8 years
solution
we consider here principal amount P = x
then amount equation will be
amount = P ×[tex]( 1+r)^{t}[/tex] ......................1
here P is initial principal amount and r is rate and t is time
54000 = x ×[tex]( 1+r)^{72}[/tex]
x = [tex]\frac{54000}{( 1+r)^{72}}[/tex] .......................3
67000 = x ×[tex]( 1+r)^{96}[/tex]
x = [tex]\frac{67000}{( 1+r)^{96}}[/tex] .........................4
so from equation 3 and 4 we get
[tex]\frac{54000}{( 1+r)^{72}}[/tex] = [tex]\frac{67000}{( 1+r)^{96}}[/tex]
solve it we get r
r = 0.9028 %
and x will be then from equation 3
x = [tex]\frac{54000}{( 1+0.009028)^{72}}[/tex]
x = 28272.36
so initial principal amount is $ 28272.36
and
interest rate after 7 year is
interest rate = [tex]\frac{0.009028}{2}[/tex] = 0.4514 %
and
amount after 8 year will be
amount = 28272.36 × [tex](1+0.009028)^{84}[/tex] × [tex](1+0.004514)^{12}[/tex]
amount after 8 year is = $63489.85