Answer: 50.
- A 50
- B 10
- C 15
- D 2
Correct answer: A. 50
Explanation: Sum = mean × number of observations = 10 × 5 = 50.
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