Answer: l + (n/2 - F)/f × h.
- A l + (n/2 - F)/f × h
- B l + (n - F)/f × h
- C l + (f₁ - f₀)/(2f₁ - f₀ - f₂) × h
- D sigma(fx)/sigma(f)
Correct answer: A. l + (n/2 - F)/f × h
Explanation: Median (grouped) = l + [(n/2 - F)/f] × h, where l = lower limit, F = cumulative freq before median class, f = freq of median class, h = class width.
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