 Hello and welcome to the session. In this session, we are going to discuss the following question and the question says that calculate the median of the following table. Here, the distribution is given such that the marks are given in the range of 1 to 10, 11 to 20, 21 to 30, 31 to 40, 41 to 50, with the corresponding frequency given by 5, 13, 18, 7 and 4. For continuous series, median md is given by the formula l plus i upon f into n by 2 minus c, where n is the sum of the frequencies denoted by summation f, n by 2 is the median number, is the lower limit of the median class, the frequency of the class just lower than the median class of the median class, frequency of the median class. Key idea, we shall proceed with the solution. Since we are given an inclusive series, so first we convert it into exclusive one by deducting 0.5 from the lower limit and adding 0.5 to the upper limit. So, the given distribution can be written like this. Now, we shall find cumulative frequency, the first entry in the cumulative frequency column will be same as that of frequency, that is 5, next will be 5 plus 13, that is 18, 18 plus 18, 36, 36 plus 7, 43, 43 plus 4, 47. Here, is equal to sum of the frequencies, that is 47 and median number is given by n by 2, that is 47 by 2 which is equal to 23.5. Now, cumulative frequency just greater than 23.5 is 36 whose class interval is 20.5 to 30.5 which is the median class. Therefore, the median class is 20.5 to 30.5. Now, using the key idea, we know that for continuous series, median is given by l plus i upon f into n by 2 minus c, where l is the lower limit of the median class, that is 20.5, i is the width of the median class given by 30.5 minus 20.5, that is 10, f is the frequency of the median class, that is 18, f is equal to 18 and c is the cumulative frequency of the class just lower than the median class, that is 18, c is equal to 18. Now, substituting all these values in the formula, we get median md is equal to l, that is 20.5 plus i upon f, that is 10 upon 18 into n by 2 minus c, that is 23.5 minus 18 which is equal to 20.5 plus 10 upon 18 into 5.5 which is equal to 20.5 plus 55 upon 18, that is 20.5 plus 3.05 which is equal to 23.55, so md is equal to 23.55, hence the median marks are 23.55 which is the required answer. This completes our session, hope you enjoyed this session.