Multiple choice

The mean of 12 observations was 40. On rechecking, it was detected that the value of 106 was wrongly copied as 10, for computation of mean. Find the correct mean.

  1. 48

  2. 52

  3. 58

  4. 60

  5. 62.

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A Correct answer
Explanation

Sum of 12 observations = 12 * 40 = 480. Correct sum = 480 - 10 + 106 = 576. Correct mean = 576 / 12 = 48.

AI explanation

The original sum of the 12 observations is the product of the mean and the number of observations, giving 12 times 40, which is 480. Correcting the wrongly copied value changes the sum by subtracting 10 and adding 106, making the new sum 576. Dividing this correct sum by 12 gives the correct mean of 48.