Question

The normal annual rainfall at stations A, B and C are 170.6, 180.3 and 165.3 cm respectively. In 1987; station B was inoperative and stations A and C recorded annual precipitation of 153.0 and 145.1 cm respectively. The annual rainfall at B in that year could be estimated as

• A. 160 cm
• B. 149.05 cm
• C. 140.58 cm
• D. 156.8 cm

Answer 1

The correct option is B 149.05 cm

Let normal annual rainfall at station A, B and C are $N_A$, $N_B$ and $N_C$ respectively.

Normal annual rainfall at station B,
$N_B=180.3cm$

$1.1N_B=1.1\times 180.3=198.33cm$
$0.9N_B=0.9\times 180.3=162.27cm$

Since the value of $N_A$ and $N_C$ lies in the range $0.9N_B$ to $1.1N_B$

So, $P_B=\frac{153+145.1}{2}=149.05cm$