Economics · Ch 3 — Organisation of Data
Finding Class Frequency by Tally Marking
3.5.10
Finding Class Frequency by Tally Marking
Tally marking is the practical way to count how many observations fall in each class. Go through the raw data one value at a time and place a stroke ( / ) against the class it belongs to: a mark of 57 gives a tally to 50–60, a mark of 71 to 70–80, a mark of 40 to 40–50. …
Table Table 3.6TABLE 3.6 Tally Marking of Marks of 100 Students in Mathematics
| Class | Observations | Frequency | Class Mark |
|---|---|---|---|
| 0–10 | 0 | 1 | 5 |
| 10–20 | 10, 14, 17, 12, 14, 12, 14, 14 | 8 | 15 |
| 20–30 | 25, 25, 20, 22, 25, 28 | 6 | 25 |
| 30–40 | 30, 37, 34, 39, 32, 30, 35 | 7 | 35 |
| 40–50 | 47, 42, 49, 49, 45, 45, 47, 44, 40, 44, 49, 46, 41, 40, 43, 48, 48, 49, 49, 40, 41 | 21 | 45 |
| 50–60 | 59, 51, 53, 56, 55, 57, 55, 51, 50, 56, 59, 56, 59, 57, 59, 55, 56, 51, 55, 56, 55, 50, 54 | 23 | 55 |
| 60–70 | 60, 64, 62, 66, 69, 64, 64, 60, 66, 69, 62, 61, 66, 60, 65, 62, 65, 66, 65 | 19 | 65 |
| 70–80 | 70, 75, 70, 76, 70, 71 | 6 | 75 |