Answer: l + [(f₁-f₀)/(2f₁-f₀-f₂)] × h.
- A l + [(f₁-f₀)/(2f₁-f₀-f₂)] × h
- B l + (n/2-F)/f × h
- C Mean - Mode = 3(Mean-Median)
- D sigma(fx)/n
Correct answer: A. l + [(f₁-f₀)/(2f₁-f₀-f₂)] × h
Explanation: Mode (grouped) = l + [(f₁-f₀)/(2f₁-f₀-f₂)] × h, where f₁ = modal class freq, f₀ = prev class freq, f₂ = next class freq.
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