Correct option is A
Class Interval | Frequency (fi) | Class Mark (xi) | fi.xi |
0-10 | 6 | 5 | 30 |
10-20 | 10 | 15 | 150 |
20-30 | 9 | 25 | 225 |
30-40 | 4 | 35 | 140 |
40-50 | 11 | 45 | 495 |
Summing up:
Σfi = 6 + 10 + 9 + 4 + 11 = 40
Σfi. xi = 30 + 150 + 225 + 140 + 495 = 1040
Arithmetic Mean (x̄) = Σfi .xi / Σfi = 1040 / 40 = 26
