The mean weight of 8 students is 45.5 kg. Two more students having weights 41.7 kg and 53.3 kg join the group. What is the new mean weight?

By formula,

Mean = $\dfrac{\text{Total weight of students}}{\text{No. of students}}$

Given,

$\therefore 45.5 = \dfrac{\text{Total weight of eight students}}{8} \\[1em] \text{Total weight of eight students} = 45.5 \times 8 = 364.$

Weight of two more students are 41.7 kg and 53.3 kg

Now,

The total weight of 10 students = 364 + 41.7 + 53.3 = 459 kg.

New mean weight = $\dfrac{459}{10}$ = 45.9 kg.

Hence, new mean weight = 45.9 kg.