Multiple choice

The average of marks obtained by 10 students is x. If each observation is increased by 5, then what is the new average?

  1. x

  2. 5x

  3. x + 5

  4. None of these

  5. NA
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If every observation in a set is increased by a constant k, the average also increases by k. Thus, the new average is x + 5.

AI explanation

The original total marks for the 10 students is 10x. When each observation is increased by 5, the new total becomes 10x + 50. Using the average formula, the new average is the new total divided by 10, which is (10x + 50) / 10. This simplifies to x + 5, showing that if each observation increases by a constant, the average increases by that same constant.

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