Multiple choice

Mean of 10 numbers is 30. Later on it was observed that numbers 15, 23 are wrongly taken as 51, 32. The correct mean is

  1. 25.5

  2. 32

  3. 30

  4. 34.5
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Original sum = 10 * 30 = 300. Correct sum = 300 - 51 - 32 + 15 + 23 = 255. New mean = 255 / 10 = 25.5.

AI explanation

The original sum of the 10 numbers is 10 multiplied by 30, which is 300. The correct sum is found by subtracting the wrong values (51 and 32) and adding the correct values (15 and 23), giving 300 minus 83 plus 38, which equals 255. Dividing this correct sum of 255 by the 10 numbers gives the correct mean of 25.5.

Keep practicing — related questions