
The general formula for the amount in savings account compounded annually is given as;
[tex]\begin{gathered} A=P(1+\frac{r}{100n})^{nt} \\ \text{Where A=Amount} \\ P=\text{Initial deposit} \\ r=\text{rate} \\ n=n\text{ umber of times it is compounded annually} \\ t=\text{time} \end{gathered}[/tex]A. The equation for the value of the investment as a function of t in the current account they have is;
[tex]A(t)=\text{ \$30000(1+}\frac{5.25}{100})^t[/tex]B. The equation for the value of the investment in an account earning 5.875% interest compounded annually is;
[tex]A(t)=\text{ \$30000(1+}\frac{5.875}{100})^{t^{}}[/tex]C. The equation for the value of the investment in an account earning 5.75% compounded semi-annually; that is twice in a year is;
[tex]\begin{gathered} A(t)=\text{ \$30000(1+}\frac{5.75}{100(2)})^{2t} \\ A(t)=\text{ \$30000(1+}\frac{5.75}{200})^{2t} \end{gathered}[/tex]D. The solution for the value of the investment in an account earning 5.5% annual interest compounded quarterly; that is four times in a year;
[tex]\begin{gathered} A(t)=\text{ \$30000(1+}\frac{5.5}{100(4)})^{4t} \\ A(t)=\text{ \$30000(1+}\frac{5.5}{400})^{4t} \end{gathered}[/tex]