Find the mean, variance and standard deviation using short-cut method
Height in cms |
No. of children |
70-75 |
3 |
75-80 |
4 |
80-85 |
7 |
85-90 |
7 |
90-95 |
15 |
95-100 |
9 |
100-105 |
6 |
105-110 |
6 |
110-115 |
3 |