1. About 13 dolphins.

3. $1,947

5. y-intercept: (0, 5)

7. [latex]{8.5}^{a}=614.125[/latex]

9. [latex]x={\left(\frac{1}{7}\right)}^{2}=\frac{1}{49}[/latex]

11. [latex]\mathrm{ln}\left(0.716\right)\approx -0.334[/latex]

13. Domain: x < 3; Vertical asymptote: x = 3; End behavior: [latex]x\to {3}^{-},f\left(x\right)\to -\infty[/latex] and [latex]x\to -\infty ,f\left(x\right)\to \infty[/latex]

15. [latex]{\mathrm{log}}_{t}\left(12\right)[/latex]

17. [latex]3\mathrm{ln}\left(y\right)+2\mathrm{ln}\left(z\right)+\frac{\mathrm{ln}\left(x - 4\right)}{3}[/latex]

19. [latex]x=\frac{\frac{\mathrm{ln}\left(1000\right)}{\mathrm{ln}\left(16\right)}+5}{3}\approx 2.497[/latex]

21. [latex]a=\frac{\mathrm{ln}\left(4\right)+8}{10}[/latex]

23. no solution

25. [latex]x=\mathrm{ln}\left(9\right)[/latex]

27. [latex]x=\pm \frac{3\sqrt{3}}{2}[/latex]

29. [latex]f\left(t\right)=112{e}^{-.019792t}[/latex]; half-life: about 35 days

31. [latex]T\left(t\right)=36{e}^{-0.025131t}+35;T\left(60\right)\approx {43}^{\text{o}}\text{F}[/latex]

33. logarithmic

35. exponential; [latex]y=15.10062{\left(1.24621\right)}^{x}[/latex]

37. logistic; [latex]y=\frac{18.41659}{1+7.54644{e}^{-0.68375x}}[/latex]