In the 'less than' type of ogive, the cumulative frequency is plotted against :

1. the lower limit of the concerned class interval

2. the upper limit of the concerned class interval

3. the mid-value of the concerned class interval

4. any value of the concerned class interval

If the class intervals 40 - 44, 45 - 49, 50 - 54 etc. in a frequency table are converted into continuous form, they become

1. 40 - 45, 45 - 50, 50 - 55, etc

2. 39 - 44, 44 - 49, 49 - 54, etc

3. 39.5 - 44.5, 44.5 - 49.5, 49.5 - 54.5, etc

4. any of the above

In a grouped frequency distribution , the cumulative frequency of the last class interval denotes :

1. the frequency pertaining to that class

2. the maximum value of the variate

3. the total number of observations

4. none of these

If the lower limit of a class-interval is 48 and the class-mark is 55, then the upper limit is :

1. 60

2. 62

3. 64

4. 61