Step 1 :Given the angle of elevation $31^\circ$, the height of the screen $7.9 \mathrm{~m}$, and the height of a customer's eyes when seated $1.2 \mathrm{~m}$.
Step 2 :Calculate the height difference between the screen and the customer's eyes: $7.9 - 1.2 = 6.7 \mathrm{~m}$.
Step 3 :Use the tangent function to find the distance: $\tan(31^\circ) = \frac{6.7}{x}$.
Step 4 :Solve for x: $x = \frac{6.7}{\tan(31^\circ)} \approx 11.2 \mathrm{~m}$.
Step 5 :\(\boxed{11.2}\) meters is the closest distance that a cinema can put seats to the screen.