Answer: Doubles.
- A Stays the same
- B Doubles
- C Is halved
- D Increases by 2
Correct answer: B. Doubles
Explanation: SD scales with data. Multiplying all values by k multiplies SD by |k|. So SD doubles.
In a perfectly normal (bell-shaped) distribution, mean, median, and mode all coincide at the centre; about 68% of data falls within 1 standard deviation of the mean, 95% within 2, and 99.7% within 3 - the empirical rule used to judge how typical or extreme a value is.
Concept context
Mean, median, mode, standard deviation, and data interpretation