Number | 5 | 10 | 15 | 20 | 25 | 30 | 35 |
Frequency | 1 | 2 | 5 | 6 | 3 | 2 | 1 |
Solution:
Number (x) | Frequency (f) | fx |
5 | 1 | 5×1 = 5 |
10 | 2 | 10×2 = 20 |
15 | 5 | 15×5 = 75 |
20 | 6 | 20×6 = 120 |
25 | 3 | 25×3 = 75 |
30 | 2 | 30×2 = 60 |
35 | 1 | 35×1 = 35 |
Total | Ʃf = 20 | Ʃfx = 390 |
Mean = Ʃfx/Ʃf
= 390/20 = 19.5
Hence the mean is 19.5.