$**$Problem B: Using the Thiessen Polygon method for the area that is described in Figure P $2\mathrm{.}13($p$.62),$

which is part of Problem $2\mathrm{.}13($i$.$e$.,$ p$.62),$ determine the annual precipitation $($in inches$).$ In your analysis

consider only stations C$,$ E and F within the area boundaries with precipitation records of $4\mathrm{.}2,6\mathrm{.}0$ and $4\mathrm{.}5$

inches, respectively $($i$.$e$.,$ ignore all other stations