Solution:
Computation of variance
Class-interval | mid-values | Frequency | ||
0-6 6-12 12-18 | 3 9 15 | 2 4 6 | 6 36 90 | 18 324 1350 |
Consider the frequency distribution
The variance of the above frequency distribution, is
Computation of variance
Class-interval | mid-values | Frequency | ||
0-6 6-12 12-18 | 3 9 15 | 2 4 6 | 6 36 90 | 18 324 1350 |