(1) Recall the formula for the average value of f over axb:

favg=1baabf(x)dx

Here a=0 and b=180:

11800180f(x)dx

(3) Use Δx=15 in Simpson’s Rule:

\begin{align*} \int_{0}^{180}f(x)dx \quad \approx\quad S_{12} &\quad=\quad \frac{15}{3}\Big(21+4(21.3)+2(21.5)+\cdots+4(21.3)+21.2)\Big) \end{align*} ParseError: Invalid delimiter 'undefined' after '\Big'

(4) Plug into average value formula:

favgS1218021.2