Question 851521
The interest rate per week is {{{6.5/52=0.125}}} %.  The specific growth model is {{{highlight_green(90000=p*1.00125^(52t))}}} and t is time in years.  The calculation being done here next assumes that the baby is newborn, less than one week old.


Know that if y is years, then {{{y*years(52*weeks/year)=numberWeeks}}};
t/52=y, and {{{t=52y}}}


{{{90000/(1.00125)^(52t)=p}}}
substituting for t=18,
{{{p=90000/(1.00125)^(52*18)}}}
-
Using a calculator instead of any table of logarithms,{{{highlight(p=27953)}}}.