Answer:
This is an exponential model.
Step-by-step explanation:
The formula for compound interest is
[tex]y=a(1+\frac{r}{n})^{nt}[/tex], where a is the principal, r is the interest rate, n is the number of times per year the interest is compounded, and t is the number of years.
Since the number of years will be a variable, we have an equation raised to a power of x; this is an exponential function.
The equation for this would be
[tex]y=400(1+\frac{0.1}{1})^{1t}\\\\y=400(1+0.1)^t\\\\y=400(1.1)^t[/tex]