The mean weight per student in a group of 7 students is 55 kg.
Question:

The mean weight per student in a group of 7 students is 55 kg. The individual weights of 6 of them (in kg) are 52, 54, 55, 53, 56 and 54. Find the weight of the seventh student.

Solution:

The mean weight per student in a group of 7 students = 55 kg

Weight of 6 students (in kg) = 52, 54, 55, 53, 56 and 54

Let the weight of seventh student = x kg

$\therefore$ Mean Weight $=\frac{\text { Sum of weights }}{\text { Total no. of students }}$

$\Rightarrow 55=\frac{52+54+55+53+56+54+x}{7}$

⇒ 385 = 324 + x

⇒ x = 385 − 324

⇒ x = 61 kg

∴ weight of seventh student = 61 kg.

Administrator