Question

arithmetic mean of nine observation is calculated as 38. But in doing so, mistakenly the observation 27 is taken instead of 72. find the actual mean of the data

Answer 1

Given, mean, 
No of observations, n = 9
We know,
Arithmetic mean of x1, x2, x3, …, xn (n observations) is


⇒ sum of observations = x1 + x2 + …+ x9 = 342
As, 27 is mistaken for 72, therefore, actual sum of observations will increase by (72 - 27) = 45
⇒ Actual sum of observations = 342 + 45 = 387


Hence, new mean is 43.

Answer 2

Step-by-step explanation:

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