What is the magnitude of the electric field midway between two point charges, -15.0 μC and 11.9 μC, that are 8.74 cm apart?
a) 1.68 × 10⁶ N/C
b) 2.47 × 10⁶ N/C
c) 3.94 × 10⁶ N/C
d) 6.37 × 10⁶ N/C