In the direct method, Mean = ?
AΣ (fᵢ · xᵢ) / Σ fᵢ
BΣ fᵢ / Σ xᵢ
CΣ (fᵢ + xᵢ) / Σ fᵢ
DΣ xᵢ / Σ fᵢ
Answer & Solution
Correct answer: A. Σ (fᵢ · xᵢ) / Σ fᵢ
Each interval is represented by its class mark xᵢ with frequency fᵢ. Mean = Σ(fᵢ·xᵢ) / Σfᵢ — the weighted average across the intervals.
Related questions
In the rainfall data for 14 Kerala districts during a week of September 2015, the value 89For a set of numbers in arithmetic sequence, which statement about the mean and median is If 25 children are sorted by haemoglobin levels with counts (2, 3, 5, 6, 4, 3, 2) at the lFor 10 values, with the high-income household excluded, the median monthly income is foundThe median of the eleven monthly incomes (with the high-income household included) equals:If one new household with a monthly income of 175 000 rupees joins the same neighbourhood,The monthly incomes of 10 households (in rupees) are 16500, 21700, 18600, 21050, 19500, 17Variance of constants is: