The median of the following data is 525. Find the values of x and y, if the total frequency is 100. Class intervals | Frequency 0 - 100 | 2 100 - 200 | 5 200 - 300 | x 300 - 400 | 12 400 - 500 | 17 500 - 600 | 20 600 - 700 | y 700 - 800 | 9 800 - 900 | 7 900 - 1000 | 4