Question

The mean weight of 9 students is 25kg .If one more student is joined in the group the mean is not altered,then the weight of the 10th student is

Answer 1

Answer:

25.

Step-by-step explanation:

avg. weight didn't get altered means average weight is constant.

so, last guy has weight 25kg

Answer 2

Answer:-

Let the sum of the weights of 9 students be "x".

Given:

Mean of their weights = 25 kg.

We know that,

Mean = Sum of observations/Number of observations

Hence,

x/9 = 25

→ x = 25*9

→ x = 225

Let the weight of 10th student be "y".

If the weight is added to the sum the mean remains same.

→ (x + y)/9 + 1 = 25

→ (225 + y) / 10 = 25

→ 225 + y = 25*10

→ 225 + y = 250

→ y = 250 - 225

→ y = 25

Therefore, the weight of the 10th student is 25 kg.