state gov TSPSC Forest Beat Officer (ఫారెస్ట్ బీట్ ఆఫీసర్) Mock Test 2023 Quantitative Aptitude Elementary Statistics
Calculate variance of the following data :
| Class interval | Frequency |
| 4-8 | 3 |
| 8-12 | 6 |
| 12-16 | 4 |
| 16-20 | 7 |
Mean (x̅) = \(\rm\frac{f_ix_i}{f_i}=\frac{3\times6+6\times10+4\times14+7\times18}{20}=13\)
1
15
2
19
3
30
4
24