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

If x and y are the lower limit and upper limit respectively of a class interval, then (y - x) gives the :

1. class mark

2. class size

3. range

4. frequency

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

If the class-intervals in a frequency distribution are 1 - 11, 11 - 21, 21 - 31, etc., then class 1 - 11 means :

1. more than 1 and less than 11

2. 1 or more but less than 11

3. equal to or more than 1 but equal to or less than 11

4. more than 1 but less than or equal to 11