## Trigonometry (11th Edition) Clone

$73^{\circ}F$
To find the average temperature in April, we need to substitute $x=4$ in the equation and solve: $f(x)=12\sin[\frac{\pi}{6}(x-3.9)]+72$ $f(x)=12\sin[\frac{\pi}{6}(4-3.9)]+72$ $f(x)=12\sin[\frac{\pi}{6}(0.1)]+72$ $f(x)=12\sin[\frac{0.1\pi}{6}]+72$ $f(x)=0.628+72$ $f(x)=72.628\approx73$ Therefore, the average temperature in April is $73^{\circ}F$.