An exponential growth model has the form:
[tex]P=P_0(1+r)^n_{}[/tex]
we know that the initial population was 3000 and that after seven years the population was 3525, plugging this vales and solving for the unknown we have:
[tex]\begin{gathered} 3525=3000(1+r)^7 \\ (1+r)^7=\frac{3525}{3000} \\ 1+r=\log _7(\frac{3525}{3000}) \\ 1+r=0.083 \end{gathered}[/tex]
Therefore the missing part of the function is 0.083
