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Question
Find the mean of all odd numbers from 5 to 20. Find the new mean when each number is multiplied by 4.
Solution
The numbers are:
5, 7, 9, 11, 13, 15, 17, 19
`barx = (x_1 + x_2 + x_3 + .... + x_n)/n`
n = 8
⇒ `barx = (5 + 7 + 9 + 11 + 13 + 15 + 17 + 19)/8 `
⇒ `barx = 96/8`
⇒ `barx = 12`
Therefore, Mean of odd numbers from 5 to 20 = 12
If numbers are multiplied by 4, the numbers are:
20,28, 36, 44, 52, 60, 68, 76
`barx = (x_1 + x_2 + x_3 + .... + x_n)/n`
n = 8
⇒ `barx = (20 + 28 + 36 + 44 + 52 + 60 + 68 + 76 )/8`
⇒ `barx = 384/8`
⇒ `barx = 48`
Therefore, Mean of odd numbers from 5 to 20 when multiplied by 4= 48
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