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Average of 5 consecutive numbers is n. If next 4 numbers are been included to the series. What will be the change in average?
Average of 5 consecutive numbers is n. If next 4 numbers are been included to the series. What will be the change in average?
1). Remains same
2). Increases by 1
3). Increases by 1.5
4). Increases by 2
1 answers
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As per given data -
Average of 5 consecutive numbers is n.
⇒ The middle number of consecutive number series will be n.
Series will be - (n - 2), (n - 1), n, (n + 1), (n + 2)
When next 4 numbers are been included in series -
New series will be - (n - 2), (n - 1), n, (n + 1), (n + 2), (n + 3), (n + 4), (n + 5), (n + 6)
Average of new 9 numbers = addition of 9 numbers ÷ 9
Average of new 9 numbers = (n - 2 + n - 1 + n + n + 1 + n + 2 + n + 3 + n + 4 + n + 5 + n + 6) ÷9
Average of new 9 numbers = (9n + 18)/9
∴ Average of new 9 numbers = n + 2