Calculate the mean of the following table:
|
Interval |
fi |
|
0-10 |
6 |
|
10-20 |
5 |
|
20-30 |
7 |
|
30-40 |
8 |
|
40-50 |
3 |
1
25.7
2
27.7
3
23.9
4
21.4
5
Not Attempted