The table given below shows the frequency distribution of the scores obtained by 200 candidates in an entrance examination. Find the median of the given data by drawing ogive.

Score	No. of students
400`-`450	`20`
450`-`500	`30`
500`-`550	`28`
550`-`600	`26`
600`-`650	`24`
650`-`700	`22`
700`-`750	`18`
750`-`800	`32`