Answer: Perfect positive correlation.
- A No correlation
- B Perfect negative correlation
- C Perfect positive correlation
- D Some positive correlation
Correct answer: C. Perfect positive correlation
Explanation: r = +1 indicates perfect positive linear correlation. As one variable increases, the other increases proportionally.
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