Present the following data in the form of 'less than' ogive and 'more than' Class (Mark obtained) Number of student 0-10 5 10-20 10 20-30 12 30-40 20 40-50 13 50-60 20 60-70 18 70-80 02
Answers
Less than ogive curves: Here now all the data are changed into the less than the cumulative frequency distribution
Marks Cumulative Frequency
Less than 10 3
Less than 20 3 + 4 = 7
Less than 30 7 + 8 = 15
Less than 40 15 + 10 = 25
Less than 50 25 + 3 = 28
Less than 60 28 + 2 = 30
The above curve is drawn successively using the method by plotting them against the upper limit of the class intervals.
More than ogive curves: Using this specific method, frequencies get cumulated and shown in a graph relevant to the lower limits of the complete classes inside the frequency distribution.
Marks Cumulative Frequency
More than 0 30
More than 10 30 - 3 = 27
More than 20 27 - 4= 23
More than 30 23 - 8 = 15
More than 40 15 - 10 = 5
More than 50 5- 3 = 2
More than 60 2-2= 0
The above curve is made by drawing the frequencies against some lower limits of the intervals in the class. And these points are used to join and obtain more than ogive curve.