Problem $4(50$ Points$)$

The elevation of Point $\backslash (\backslash$mathrm$\{$A$\}=4545\mathrm{.}75\backslash ).$

Develop the observation equations for adjusting this network by least squares, using the following elevation differences.

For the leveling network shown above, calculate using Excel: $(1)$ the most probable elevations for B$,$ C$,$ and D and their $(2)$ standard deviations.

The observed values and line length $($in miles$)$ are given in the table. Apply appropriate weights in the computations. Compute the $(3)$ reference standard deviation, and $(4)$ tabulate the adjusted observations and $(5)$ their residuals. Submit computed EXCEL file.