Answer: non-negative.
- A non-negative
- B negative
- C exactly zero
- D below the mean
Correct answer: A. non-negative
Explanation: Variance is a mean of squared deviations, so it can never be negative.
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