Answer: Compare variability between datasets with different means.
- A Find the mean value of a single data set
- B Compare variability between datasets with different means
- C Measure the correlation between two distinct variables
- D Find the quartile boundaries of a frequency distribution
Correct answer: B. Compare variability between datasets with different means
Explanation: CV = (SD/mean) × 100%. Allows comparison of variability between datasets with different scales.
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