453 nC/m lies at the center of a spherical, conducting shell of inner and outer radii 3.50R and 4.00R, respectively. If the conducting shell carries a total charge of Q = 40.5 nC, find the magnitude of the electric field at the given radial distances from the center of the charge distribution. 0.660R N/C R 3.90R: N/C 3.50R 4.0OR 1.90R: N/C 4.70R: N/C