2019 · Q2
Directions: Read the following frequency distribution for two series of observations and answer the two items that follow:
| Class interval | Series-I | Series-II |
|---|---|---|
| 10–20 | 20 | 4 |
| 20–30 | 15 | 8 |
| 30–40 | 10 | 4 |
| 40–50 | X | 2X |
| 50–60 | Y | Y |
| Total | 100 | 100 |
What is the mode of the frequency distribution of Series-II?
Elementary MathematicsStatistics
- A26
- B36
- C46
- D56
Explanation
From Q1, X = 29 and Y = 26, so Series-II frequencies are 4, 8, 4, 58, 26. The modal class is 40-50 (highest frequency 58). Mode = l + h(f1-f0)/(2f1-f0-f2) = 40 + 10x(58-4)/(116-4-26) = 40 + 540/86 = 46.28, i.e. 46 among the options.