Standard difficulty · 20 questions · 40 marks · Time: 38 minutes
Write full answers in Sections B and C. Answers are on the last page — try every question first!
Measures of Central Tendency · AW-11SS-ECT-2026-V1 · For parents — fold back or tear off before handing the sheet to your child.
| Q | Answer | Working |
|---|---|---|
| 1 | (d) arithmetic mean | — |
| 2 | (a) 81 | 486 ÷ 6 = 81 |
| 3 | (d) 24 | in order: 10, 20, 22, 24, 46, 67, 88; the middle value |
| 4 | (b) 53 | 53 occurs 3 times, more than any other value |
| 5 | (a) 146.05 | Σfx ÷ Σf = 6,280 ÷ 43 |
| 6 | (d) 75 | 4 × 75 − 225 = 75 |
| 7 | (b) 79.33 | (65 × 3 + 98 × 4 + 73 × 5) ÷ 12 |
| 8 | (c) 22th | (N + 1) ÷ 2 with N = 43 |
| 9 | A single value that represents a whole set of data, such as the mean, median or mode. | — |
| 10 | Σd = −50; mean = 50 | d = X − 60; mean = 60 + Σd ÷ 5 |
| 11 | 43.07 | N ÷ 2 = 48.5; median class 40–45: L = 40, c.f. = 35, f = 22, h = 5 |
| 12 | 72.31 | modal class 60–80: L = 60, D1 = 8, D2 = 5, h = 20; L + D1 ÷ (D1 + D2) × h |
| 13 | 70 | (N + 1) ÷ 2 = 20.5; cumulative frequencies 8, 13, 19, 34, 40 |
| 14 | 86 | 3(N + 1) ÷ 4 = 6th item: item 6 |
| 15 | 45.50 | Σfm ÷ Σf = 4,595 ÷ 101 |
| 16 | about 16,240, 14% | (100 − 86)% of 116,000 |
| 17 | The mean uses all values but is pulled by extremes; the median is the middle value and resists extremes; the mode is the most frequent value and suits the most typical size or choice. | — |
| 18 | (a) ₹152.86 (b) ₹147.27 (c) the mean | mean = Σfm ÷ Σf; median = L + ((N ÷ 2 − c.f.) ÷ f) × h |
| 19 | Σfd′ = −34; mean = 51.70 | d′ = (m − 55) ÷ 10; mean = A + (Σfd′ ÷ Σf) × c |
| 20 | (a) ₹29,500 (b) ₹13,000 (c) the median, because the mean is pulled up by one very high income | 147,500 ÷ 5; middle value in order |