The mean weight of 10 students is 55 kg. If a student with weight 60 kg joins the group, what is the new mean weight?
Answer: B
Original sum of weights = 10 × 55 = 550 kg.
Weight of the new student = 60 kg.
New total weight = 550 + 60 = 610 kg.
New number of students = 10 + 1 = 11.
New mean weight = \(\frac{610}{11} \approx 55.45\) kg.