Question 917118
 In General {{{A(t) = P(1+r/n)^(nt)}}}
A = Accumulated Amount
P= principal = 
r= annual rate = .15
n= periods per year = 12
{{{4500/2500 = (1+.15/12)^(12t)}}}
{{{log(1.8)/12log(1.0125)}}} = t