Question 102467
The main question to be answered is: how many years have passed by
since the year of purchase and the years in question, 2007 and 
2008? Between 1998 and 2000, there are 2 years, Then between 2000
and 2007 there are 7 years, So there are 9 years between 1998 and
2007. That means there are 10 years between 1998 and 2008.
  Just solve the formula for 10 years, then for 9 years, and take
the difference.
{{{f(10) = 50000(1.05)^10}}}
{{{f(10) = 50000*1.6289}}}
{{{f(10) = 81445}}}
then
{{{f(9) = 50000(1.05)^9}}}
{{{f(9) = 50000*1.5513}}}
{{{f(9) = 77566}}}
{{{81445 - 77566 = 3879}}} answer to the nearest dollar