The weights (in kg) of 15 students are:

Given the numbers are 31, 35, 27, 29, 32, 43, 37, 41, 34, 28, 36, 44, 45, 42, 30

Arranging the numbers in ascending order

27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 41, 42, 43, 44, 45.

n = 15 (odd)

$\therefore$ New Median $=\left(\frac{\mathrm{n}+1}{2}\right)^{\text {th }}$ value

$=\left(\frac{15+1}{2}\right)^{\text {th }}$ value

$=8^{\text {th }}$ value $=35 \mathrm{~kg}$

If the weight 44 kg is replaced by 46 kg and 27 kg is replaced by 25 kg

Then the new values be in order are: 25, 28, 29, 30, 31, 32, 34, 35, 36, 37, 41, 42, 43, 45, 46

$\therefore$ New Median $=\left(\frac{\mathrm{n}+1}{2}\right)^{\text {th }}$ value

$=\left(\frac{15+1}{2}\right)^{\text {th }}$ value

$=8^{\text {th }}$ value $=35 \mathrm{~kg}$