Multiple choice

The mean of 20 observations is 31. If each observation is multiplied by 31, then find the value of the new mean.

  1. $971$
  2. $961$
  3. $956$
  4. $991$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When every observation in a dataset is multiplied by a constant, the mean is also multiplied by that constant. New mean = old mean × multiplier = 31 × 31 = 961. This is a fundamental property of arithmetic mean.

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