Prob$/$em $5$: It is required to establish the elevation of point $B$ from point $A($elevation $187\mathrm{.}298m).$ Points A and $B$ are on opposite sides of a ten$-$lane highway. Reciprocal leveling is used, with the following results:

Set up at A side of highway: Rod reading on $A=0\mathrm{.}673m$ Rod readings on $B=2\mathrm{.}416$ and $2\mathrm{.}418m$

Setup at $B$ side of highway: Rod reading on $B=2\mathrm{.}992m$ Rod readings on $A=1\mathrm{.}254$ and $1\mathrm{.}250m$

$($a$)$ What is the elevation of point $B?$

$($b$)$ What is the leveling error?

Problem $6$: Compute the error due to curvature and refraction for the following

distances:

$($a$)400m$

$($b$)3,000m$

$($c$)2,000ft($d$)2\mathrm{.}7$ miles $($e$)4$ kilometers

Problem $7$: An offshore drilling rig is being towed out to sea. What is the maximum distance away that the navigation lights can still be seen by an observer standing at the shoreline? The observer's eye height is $5^{\text{'}}{6}^{\text{'}\text{'}},$ and the uppermost navigation light is $280ft$ above the water.

Solve problems $5,6,7$