The table below shows Annual Precipitation recorded by 10 weather stations, within Lahore City. The actual coordinates of the stations are provided. You are required to estimate the average rainfall over Lahore City (boundary has been defined) by Isohyetal Method on excel sheet

Points Boundary Coordinates
1    31°22'00"N       74°14'00"E
2    31°22'00"N       74°24'00"E
3    31°34'00"N       74°14'00"E
4    31°34'00"N       74°24'00"E

Sr.         Station Coordinates         Annual Precipitation

1 A 31°27'29.0"N 74°19'13.1"E        251
2 B 31°28'22.8"N 74°17'31.6"E      360
3 C 31°25'44.0"N 74°16'59.8"E     320
4 D 31°27'10.0"N 74°13'58.7"E     294
5 E 31°21'54.0"N 74°16'56.0"E      425
6 F 31°22'56.0"N 74°23'52.6"E       395
7 G 31°34'36.8"N 74°24'41.3"E      370
8 H 31°35'43.1"N 74°20'00.7"E       280
9 I 31°34'04.7"N 74°17'27.3"E         357
10 J 31°32'45.5"N 74°19'24.4"E       384

Perform the required calculations using appropriate tables. and draw contours on graph and provide excel sheet