Find Measurement of the Side of a Square Floor Tile $\frac { 1 } { 78 }$

Multiple Choice

Find measurement of the side of a square floor tile is 14 inches, with a possible error of $\frac { 1 } { 78 }$ inch. Use differentials to approximate the possible propagated error in computing the area of the square.

A) $\pm \frac { 14 } { 117 }$ square inches
B) $\pm \frac { 7 } { 78 }$ square inches
C) $\pm \frac { 7 } { 39 }$ square inches
D) $\pm \frac { 14 } { 39 }$ square inches
E) $\pm \frac { 1 } { 156 }$ square inches