SOLUTION: The average of 14 students of class is 15.3. A new student is added. The average becomes 15.25. What is the height of the new added student .

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Question 1006332: The average of 14 students of class is 15.3. A new student is added. The average becomes 15.25. What is the height of the new added student .
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
14 * 15.3 = 214.2
15 * 15.25 = 228.75
difference is 228.75 - 214.2 = 14.55
the height of the new student is 14.55

average = total / number of students.

from this equation, you get:

total = number of students * average.

you have the average of the 14 students.
multiply the average of 15.3 by 14 to get the total of 214.2.

you have the average of the 15 students.
multiply the average of 15.25 by 15 to get the total of 228.75.

subtract 214.2 from 228.75.

the difference of 14.55 has to be the height of the 15th student.