Answer
The angular deviation is $~~0.214~rad$
Work Step by Step
We can find the angular deviation of the third-order bright fringe:
$\theta_3 = \frac{m\lambda}{d}$
$\theta_3 = \frac{(3)(550\times 10^{-9}~nm)}{7.70\times 10^{-6}~m}$
$\theta_3 = 0.214~rad$
The angular deviation is $~~0.214~rad$
