Benchmark A $($BM A$)$ elevation $100\mathrm{.}00$ is sighted with a differential level from point C with a rod

reading of $6\mathrm{.}15$ ft$.$ From point C a rod reading of $4\mathrm{.}52$ ft$.$ is obtained by point D$.$ If a building

foundation at point D is supposed to be at $102\mathrm{.}10$ ft$.$ is the foundation above or below the

ground elevation at point D and by how much?