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28 votes
28 votes
The average height of 10 pupils is 140cm if a new pupil joined the group the average height of 11 pupils become 148

cm find the height of new pupils ​

User David Reynolds
by
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1 Answer

20 votes
20 votes

Answer:

228 cm

Explanation:

the average is calculated as

average =
(sum)/(count) , then


(sum)/(10) = 140 ( multiply both sides by 10 to clear the fraction )

sum = 1400

let the height of new pupil be x , then


(sum+x)/(11) = 148 ( multiply both sides by 11 )

sum + x = 1628 , that is

1400 + x = 1628 ( subtract 1400 from both sides )

x = 228

height of new pupil is 228 cm

User Dylan Cross
by
3.1k points