Answer:
23.26 years
Step-by-step explanation:
Use the compound interest formula:
A = P [tex]( 1 + \frac{r}{100n} )^{nt}[/tex]
A = final amount
P = initial principal balance
r = interest rate
n = number of times interest applied per time period
t = number of time periods elapsed
P = $2,136.70
r = 2.7
n = 4
A = $4,000
Now we plug everything in and solve for t.
$4,000 = $2,136.70 [tex](1 + \frac{2.7}{100 * 4} )^{4t}[/tex]
$4,000 = $2,136.70 [tex](1 + .00675 ) ^{4t}[/tex]
$4,000 = $2,136.70[tex](1.00675)^{4t}[/tex] Divide each side by $2,136.70
$4,000/$2,136.70 = [tex](1.00675)^{4t}[/tex]
1.87 = [tex](1.00675)^{4t}[/tex]
log (1.87) = log [tex](1.00675)^{4t}[/tex]
log 1.87 = (4t) (log 1.00675) Divide each side by (log 1.00675)
[tex]\frac{log 1.87}{log 1.00675}[/tex] = 4t
93.044 = 4t Divide each side by 4.
93.044/4 = t
23.26 = t
23.26 years
