 Hi and welcome to our session. Let us discuss the following question. The question says calculate the mean deviation about median age for the age distribution of 100% given below. This is the data given to us and we have to calculate mean deviation about median. With the solution we will first make a table. Now as the other class intervals are 16 to 20, 21 to 25 so we will first convert this into continuous frequency distribution by subtracting 0.5 from the lower limit and adding 0.5 to the upper limit of each class interval. So after doing this we get class intervals as 16.5 to 20.5, 20.5 to 25.5 and so on and we have also written the corresponding frequencies of each class interval. We will find midpoint of each class interval. Now midpoint of this class interval is equal to 15.5 plus 20.5 divided by 2 and this is equal to 80, midpoint of this class interval is 23, midpoint of class interval 25.5 to 30.5 is 28. Similarly we have written midpoint of each class interval. Now we will write the cumulative frequency. In the first row we will have 5, then we have 5 plus 6 that is 11, 11 plus 12 is 23, 23 plus 14 is 37, 37 plus 26 is 63, 63 plus 12 is 75, 75 plus 16 is 91, 91 plus 9 is 100. Now we will find n, n is equal to summation i goes from 1 to 8 if i on adding all these frequencies we get 100. Now 100 is even and we know that if n is even then the median class is that class interval whose cumulative frequency is equal to or just greater than n by 2 observation. So n by 2 is 50 so the class interval containing item 35.5 to 45 sorry 40.5. The cumulative frequency of preceding 35 quantity of median class is minus 20 and mod of minus 20 is 20. Equal to minus 15 mod of minus 15 is 15. X i minus is 100 is 90, 12 into 10 is 120, 14 into 5 is 70, 26 into 0 is 0, 12 into 5 is 60, 16 into 10 is 160, 9 into 15 is 135. On adding all this we get 735. X i minus n is equal to 735 mean deviation about median. Mean deviation about median is equal to 1 by n into summation i goes from 1 to 8 if i into mod and this is equal to 1 by 100 into 735 and this is equal to 7.35. So the required answer is 7.35 so this completes the session i and take care.