Refer to Interactive Solution $\underline{19.33}$ at to review a method by which this problem can be solved. The electric field has a constant value of $4.0 \times 10^{3} \mathrm{~V} / \mathrm{m}$ and is directed downward. The field is the same everywhere. The potential at a point $P$ within this region is $155 \mathrm{~V}$. Find the potential at the following points: (a) $6.0 \times 10^{-3} \mathrm{~m}$ directly above $P$, (b) $3.0 \times 10^{-3} \mathrm{~m}$ directly below $P$, (c) $8.0 \times 10^{-3} \mathrm{~m}$ directly to the right of $P$.