Answer:
$6,506.51
Step-by-step explanation:
Recall that increasing an amount C in x% is equivalent to multiply it by (1+x/100)
As we have 4% APR, the monthly interest would be (4/12)% = 0.04/12
Month 0 (first payment)
$250
Month 1
[tex]250 + 250 \frac{0.04}{12}= 250(\frac{12.04}{12})[/tex]
Month 2
[tex]250(1+\frac{12.04}{12}+(\frac{12.04}{12})^2)[/tex]
Month 3
[tex]250(1+\frac{12.04}{12}+(\frac{12.04}{12})^2+(\frac{12.04}{12})^3)[/tex]
Month 24 (2 years)
[tex]250(1+\frac{12.04}{12}+(\frac{12.04}{12})^2+(\frac{12.04}{12})^3+...+(\frac{12.04}{12})^{24})[/tex]
The sum
[tex]1+\frac{12.04}{12}+(\frac{12.04}{12})^2+(\frac{12.04}{12})^3+...+(\frac{12.04}{12})^{24}[/tex]
is the sum of the first 24 terms of a geometric sequence with common ratio [tex]\frac{12.04}{12}[/tex] which is
[tex]\frac{1-(12.04/12)^{25}}{1-(12.04/12)}=26.02603071[/tex]
so, after 2 years the saving balance is
250*26.02603071 = 6,506.50767= $6,506.51 rounded to the nearest cent.