Answer:
$13,52.60
Step-by-step explanation:
The formula to apply is
[tex]A=P(1+\frac{r}{n} )^{nt}[/tex]
where
A= amount of money at the end
P=the amount of money to invest, principal
r=rate of interest in decimal
n=number of compoundings per year
t=time in years
Given that;
t=4 years
A=$18000
P=?
r=0.08
n=2
Substitute values in the formula
[tex]A=P(1+\frac{r}{n} )^{nt} \\\\\\18000=P(1+\frac{0.08}{2} )^{2*4} \\\\\\18000=P(1+0.04)^8\\\\\\18000=P(1.04)^8\\\\\\18000=1.36856905041P\\[/tex]
Divide both sides by 1.36856905041 to remain with P
[tex]\frac{18000}{1.36856905041} =\frac{1.36856905041P}{1.36856905041}[/tex]
P=$13152.56