Mean weight of a group of 30 students is 62.5 kg . A student (weight 71.5 kg) left the group and a new student (weight 53.5 kg) joined the group. The new mean of the group will be 60 kg
63.5kg
61.9 kg
59.5 kg
Answers
Answer:
61.9 kg
Explanation:
Mean of 30 students = 62.5
New mean =( (30 × 62.5) -- 71.5 +53.5)%30 kg
= 61.9 kg
#answerwithquality and # BAL.
The new mean weight of the group of 30 students is equal to 61.9 kg.
Given:
The mean weight of a group of 30 students is equal to 62.5 kg.
A student with a weight of 71.5 kg leaves the group.
A new student with a weight of 53.5 kg joins the group.
To Find:
The new mean weight of the group.
Solution:
→ Mean is the average of a given data set and it is calculated by dividing the sum of given data by the total number of data.
→ The mean of 'N' observations is equal to the sum of all the 'N' observations divided by the total number of observations.
∵ The mean weight of the group of 30 students is equal to 62.5 kg.
∴ The sum of the weights of these 30 students = 62.5 × 30 = 1875 kg
→ Since a student with a weight of 71.5 kg leaves the group and a new student with a weight of 53.5 kg joins the group:
∴ The sum of the weights of the 30 students = 1875 - 71.5 + 53.5 = 1857 kg
∴ The new mean weight of the group of 30 students = 1857/30 = 61.9 kg
Therefore the new mean weight of the group of 30 students would be equal to 61.9 kg.
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