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Finding Median Graphically Marks inclusive series Conversion into exclusive series No. of students cumulative Frequency (x) (f) (C. M) 410-419 409. 5-419. 5 14 14 420-429 419. 5-429. 5 20 34 430-439 429. 5-439. 5 42 76 440-449 439. 5-449. 5 54 one hundred thirty 450-459 449. 5-459. 5 45 175 460-469 459. 5-469. 5 18 193 470-479 469. 5-479. 5 7 cc The median(prenominal) value of a series may be determinded through the graphic innovation of data in the form of ogives. This can be done in 2 ports. 1. Presenting the data graphically in the form of less(prenominal) than ogive or more than ogive . . 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 start out Marks Cumulative Frequency (C. M) Less than 419. 5 14 Less than 429. 5 34 Less than 439. 5 76 Less than 449. 5 130 Less than 459. 5 175 Less than 469. 5 193 Less than 479. 5 200 move involved in calculating median using less tha n Ogive approach 1. Convert the series into a less than cumulative frequency dispersion as shown above . 2. Let N be the core number of students whos data is given.N allow also be the cumulative frequency of the net interval. Find the (N/2)thitem(student) and mark it on the y-axis. In this case the (N/2)thitem (student) is 200/2 = 100thstudent. 3. Draw a perpendicular from 100 to the right to swing music the Ogive curve at point A. 4. From point A where the Ogive curve is put off, 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. The median turns out to be 443. 94. 2. more than than Ogive approach More than marks Cumulative Frequency (C. M) More than 409. 5 200 More than 419. 5 186 More than 429. 166 More than 439. 5 124 More than 449. 5 70 More than 459. 5 25 More than 469. 5 7 More than 479. 5 0 Steps involved in calculating median using more than Ogive approach 1. Convert the serie s into a more than cumulative frequency distribution as shown above . 2. Let N be the total number of students whos 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)thitem (student) is 200/2 = 100thstudent. 3. Draw a perpendicular from 100 to the right to cut the Ogive curve at point A. . 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. The median turns out to be 443. 94. 3. Less than and more than Ogive approach Another way of graphical determination of median is through simultaneous graphic presentation of both the less than and more than Ogives. 1. Mark the point A where the Ogive curves cut each other. 2. Draw a perpendicular from A on the x-axis. The corresponding value on the x-axis would be the median value.