Multiple choice

The mean of $15$ observations is $32$. Find the resulting mean, if each observation is decreased by $20\%$

  1. $38.4$
  2. $40.5$
  3. $37$

  4. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When each observation in a dataset is decreased by a percentage, the mean is also decreased by that same percentage. Decreasing 32 by 20% (which is 6.4) results in 25.6. Since 25.6 is not listed, 'None of these' is the correct choice.

AI explanation

If each observation is decreased by 20%, the resulting mean will also decrease by 20% of its original value. The new mean equals 32 minus 0.20 multiplied by 32, which is 32 minus 6.4. This results in a new mean of 25.6, which is not among the listed numerical choices.

Keep practicing — related questions