Answer: Spread (variability) of data around the mean.
- A The central tendency of the data, like the mean does
- B Spread (variability) of data around the mean
- C The middle value of the data when arranged in order
- D The single largest value present in the data set
Correct answer: B. Spread (variability) of data around the mean
Explanation: Standard deviation measures how spread out values are from the mean. Higher SD = more spread.
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