Multiple choice

The mean of 40 numbers is 160. It was detected on checking that while computing the mean, the value of 165 was wrongly taken as 125. Find the correct mean.

  1. 155

  2. 159

  3. 160

  4. 161

  5. 200
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Original sum = 40 * 160 = 6400. Correct sum = 6400 - 125 + 165 = 6440. Correct mean = 6440 / 40 = 161.

AI explanation

The initial total sum of the 40 numbers is the product of the mean and the count, giving 40 times 160, which is 6400. The correct sum is found by subtracting the wrong value of 125 and adding the actual value of 165, resulting in a new sum of 6440. The correct mean is the correct sum divided by 40, which is 161.

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