Q.Using the same 12 students' marks as Example 1 (14, 18, 20, 22, 25, 26, 28, 30, 33, 35, 40, 45, already arranged in order), find P60.

For an individual series, P60 is located the same way as a quartile or decile, only at position 60N/100. …

Step 1 — Locate the position. $k = \frac{60N}{100} = \frac{60(12)}{100} = 7.2$.

Step 2 — Since 7.2 is NOT a whole number, round UP to the 8th item. From the ordered list (14, 18, 20, 22, 25 …

Plausibility cross-check against Q2 and Q3 from the same data. Q2 (the median) = 27 and Q3 = 34 for this dataset (Example 1). Since P60 locates a point BETWEEN the 50% point and the 75% point, its valu …

Rounding 7.2 DOWN to the 7th item instead of UP to the 8th — the convention for a non-whole position is always to round up, never down, otherwise the calcula …