Answer
$86^{\circ}$
Work Step by Step
Since August represents $x=7$, we substitute $x=7$ in the equation,
$t=60−30\cos(\frac{\pi}{6}x)$
$t=60−30\cos(\frac{\pi}{6}\times7)$
$t=60−30\cos(\frac{7\pi}{6})$
$t=60−30(-\frac{\sqrt 3}{2})$
$t=60-15(-\sqrt 3)$
$t=60+25.98$
$t=85.98\approx86^{\circ}$