Solution:
Given:
[tex]\begin{gathered} P=\text{ \$400} \\ r=3\text{ \%} \end{gathered}[/tex]Using the simple interest formula;
[tex]I=\frac{\text{PTR}}{100}[/tex]At t = 0 years,
[tex]\begin{gathered} I=\frac{\text{PTR}}{100} \\ I=\frac{400\times0\times3}{100} \\ I=\text{ \$0} \end{gathered}[/tex]At t = 5 years,
[tex]\begin{gathered} I=\frac{\text{PTR}}{100} \\ I=\frac{400\times5\times3}{100} \\ I=\text{ \$60} \end{gathered}[/tex]At t = 10 years,
[tex]\begin{gathered} I=\frac{\text{PTR}}{100} \\ I=\frac{400\times10\times3}{100} \\ I=\text{ \$120} \end{gathered}[/tex]At t = 15 years,
[tex]\begin{gathered} I=\frac{\text{PTR}}{100} \\ I=\frac{400\times15\times3}{100} \\ I=\text{ \$180} \end{gathered}[/tex]At t = 20 years,
[tex]\begin{gathered} I=\frac{\text{PTR}}{100} \\ I=\frac{400\times20\times3}{100} \\ I=\text{ \$240} \end{gathered}[/tex]To get the amount,
[tex]\text{Amount}=\text{principal + interest}[/tex][tex]\begin{gathered} At\text{ t = 0years,} \\ \text{Amount}=\text{principal + interest} \\ \text{Amount}=400+0=\text{ \$400} \\ \\ \\ At\text{ t = 5years,} \\ \text{Amount}=\text{principal + interest} \\ \text{Amount}=400+60=\text{ \$460} \\ \\ \\ At\text{ 10years,} \\ \text{Amount}=\text{principal + interest} \\ \text{Amount}=400+120=\text{ \$520} \\ \\ \\ At\text{ 15years,} \\ \text{Amount}=\text{principal + interest} \\ \text{Amount}=400+180=\text{ \$580} \\ \\ \\ At\text{ 20years,} \\ \text{Amount}=\text{principal + interest} \\ \text{Amount}=400+240=\text{ \$640} \end{gathered}[/tex]The table can be represented below;
The graph to represent the simple interest account is shown below;
