GATE 2018 CE (CE1) – Question 58
Six well-distributed rain gauges record depths 470, 465, 435, 525, 480, 510 mm. Their corresponding Thiessen areas are 95, 100, 98, 80, 85, 92 in units of 10000 m². Thiessen mean rainfall, to one decimal, is ______ mm.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 478.5 to 479.5
Explanation
The weighted sum is $$\bar P=\frac{470(95)+465(100)+435(98)+525(80)+480(85)+510(92)}{95+100+98+80+85+92}=479.0909\ \mathrm{mm}.$$ The common area multiplier cancels. Rounded mean: 479.1 mm.