Question

The successive annual rainfall magnitudes at a place for a period of 10 years from 2001 to 2010, both inclusive, are 30.3, 41.0, 33.5, 34.00, 33.3, 36.2, 33.6, 30.2, 35.5 and 36.3 cm. The mean and median values of this annual rainfall series are respectively

• A. 33.8 cm and 34.39 cm
• B. 34.39 cm and 33.8 cm
• C. 34.39 cm and 40.2 cm
• D. 33.8 cm and 40.2 cm

Answer 1

The correct option is B 34.39 cm and 33.8 cm

Mean value $=\frac{\sum x}{n}$
$30.3+41.0+35.5+34+33.3$
$=\underset{–}{+36.2+33.6+30.2+35.5+36.3}$
$10$
$=34.39cm$
If we arrange the various rainfall magnitude in increasing order, then we get,
$30.2,30.3,33.3,33.5,33.6,34,35.5,36.2,36.3,41.0$
If no.of terms are even, then median will
$=\left[\frac{\left(\frac{n}{2}\right)+(\frac{n}{2}+1)}{2}\right]=\frac{33.6+34}{2}=33.8cm$