Hi there!
The equation for the electric field of a point charge is given by:
[tex]E = \frac{kq}{r^2}[/tex]
E = Electric Field (N/C)
k = Coulomb's Constant
r = distance (m)
We can rearrange to solve for 'q':'
[tex]q^2 = \frac{Er^2}{k}\\\\q = \sqrt{\frac{Er^2}{k}}[/tex]
Plug in the values and solve:
[tex]q = \sqrt{\frac{(1236)(4^2)}{(8.99*10^9)}} = \boxed{0.00148 C}[/tex]
