[tex]\bf \textit{Periodic/Cyclical Exponential Decay}
\\\\
A=P(1 - r)^{\frac{t}{c}}\qquad
\begin{cases}
A=\textit{accumulated amount}\\
P=\textit{initial amount}\to &180\\
r=rate\to 3\%\to \frac{3}{100}\to &0.03\\
t=\textit{elevation feet}\to &4000\\
c=period\to &1000
\end{cases}
\\\\\\
A=180(1-0.03)^{\frac{4000}{1000}}\implies A=180(0.97)^4\implies A= 159.3527058[/tex]
periodic or cyclical, because every 1000 feet, is losing 3% of the remaining horsepower, so the every cycle of 1000 feet, 3% is getting hosed.
