Question:
The weight of 10 students (in kgs) are
55, 40, 35, 52, 60, 38, 36, 45, 31, 44
The median weight is
(a) 40 kg
(b) 41 kg
(c) 42 kg
(d) 44 kg
Solution:
(c) 42 kg
Arranging the numbers in ascending order, we have:
31, 35, 36, 38, 40, 44, 45, 52, 55, 60
Here, n is 10, which is an even number.
Thus, we have:
Median $=$ Mean of $\left(\frac{n}{2}\right)$ th observation \& $\left(\frac{n}{2}+1\right)$ th observation
Median weight $=$ Mean of the weights of $\left(\frac{10}{2}\right)$ th student \& $\left(\frac{10}{2}+1\right)$ th student
$=$ Mean of the weights of 5 th student & 6 th student
$=\frac{1}{2}(40+44)=42$
Hence, the median weight is $42 \mathrm{~kg}$.