how to calucate median from less than cummulative frequency curve
Answers
Answer:
The median value of a series may be determinded through the graphic presentation of data in the form of Ogives.This can be done in 2 ways.
1. Presenting the data graphically in the form of 'less than' ogive or 'more than' ogive .
2. Presenting the data graphically and simultaneously in the form of 'less than' and 'more than' ogives.The two ogives are drawn together.
1. Less than Ogive approach
Less than 419.5 (cf) 14Less than 429.5 (cf) 34Less than 439.5 (cf) 76Less than 449.5(cf) 130Less than 459.5 (cf) 175Less than 469.5 (cf)193 than 479.5 (cf) 200
Steps involved in calculating median using less than Ogive approach -
1. Convert the series into a 'less than ' cumulative frequency distribution as shown above .
2. Let N be the total number of students who's data is given.N will also be the cumulative frequency of the last interval.Find the (N/2)thitem(student) and mark it on the y-axis.In this case the (N/2)th item (student) is 200/2 = 100thstudent.
3. Draw a perpendicular from 100 to the right to cut the Ogive curve at point A.
4.From point A where the Ogive curve is cut, draw a perpendicular on the x-axis. The point at which it touches the x-axis will be the median value of the series as shown in the graph.
its little difficult for u to understand without graph but i wish that this ans help you