Construction of a cumulative frequency distribution table is useful in determining the

1. mean

2. median

3. mode

4. all the three measures

Construct the following frequency distribution :

The upper limit of the median class is

1. 17

2. 17.5

3. 18

4. 18.5

For the following distribution :

The sum of lower limits of the median class and modal class is

1. 15

2. 25

3. 30

4. 35