All problem$-$solving need to include the identify the techniques, i$.$e$.$ the formula$($s$)$ that you use to

solve the problem.

$9\mathrm{.}8$ A line of three$-$wire differential levels goes from benchmark Gloria

to benchmark Carey. The length of the line was determined to be

$2199m.$ The instrument had a stated compensator accuracy of $+-{0\mathrm{.}3}^{\text{'}\text{'}}.$

The instrument$-$rod combination had an estimated reading error of $+-1$

$m\frac{m}{k}m.$ The instrument is found to have an inclined collimation error

of $1\mathrm{.}0m\frac{m}{k}m,$ so the sight distances were kept to approximately $50+-$

$5m.$ If the difference in elevation observed is $15\mathrm{.}601m,$ what is the

estimated error in the final elevation difference?