 Okay, the next thing is median. So we have learned mean mean is Sigma x by n that is mean Sigma x by n x bar is the denotation of mean that is x bar It's equal to sigma x and we take the total value We add up all the values and divided by n the total number of observation 1 2 3 4 5 So we get mean Next is the median median is nothing but the middle value. Okay, we can see here I put the same example 2 3 4 5 and 6 we should put it in a ascending or descending order We should put it an ascending or descending order as a increasing or decreasing order and we should take the Middle value. So this is in a ascending order 2 3 4 5 and 6 We take the middle value. So that is 4. So median is 4 Suppose if we have an even number that is this is odd number 1 2 3 is total 5 numbers So we get exactly the middle value as 4 Suppose we have an even data set that is 2 3 4 5 6 and 7 so it is 1 2 3 4 5 6 There are 6 numbers so we should take the middle value that is the Average of middle value that is 2 values 4 and 5 is the Middle 2 values 6 7 are above the 2 values and 2 3 and below the middle value So 4 plus 5 divided by 2 that is non by 2 that is 4.5 is the median So when we should take mean and when we should take median, I'll explain you So now we understand that median is the middle value that is we should take the exact middle value if it is a odd data set odd and We should take the average of middle two values if it is an even data set Fine So mean is the total average divided by number of observations. Here we take the middle value So it represents the central tendency this region of the data set central tendency this region Fine next we'll move on to the mode This is very rarely used in any study because it is It is not giving exactly the central tendency in a big data set When we take the smaller one it gives it may gives the Central tendency but mostly we won't take mode So basically it is the most Frequent value it is the most frequent value that is suppose we take a different example That is one if if it is an exam for ten marks the first person scored one then two two three four four four five six So total one two three four five six seven eight. Okay. Let it be eight or ten or twenty Doesn't matter. We don't need to put in an increasing or decreasing order We can put randomly no problem only we need to put an increasing order for median for Mean we don't need to put any order. We can just add up and divided by total number so here we are Just randomly putting all the values and we are taking the most Highly or highest repeated value which is the number which is most repeated that is here the four is repeated three times Two is repeated twice then one three five and six Game once so the most repeated value is four so that is the Mode of this data set Suppose this is example one two two three four four five five and six most repeated value is two Four and five so all are repeated twice So two four and five becomes the mode of this data set if it is the last example or if it is example one two three Four five and six there is no mode because it is not Getting repeated in any particular number and we take the same example. This also has no mode Because it is two three four five and six all a different number So it is the most frequent value is the mode. So okay. Okay. Let me recap This is the main median and mode are the measure of central tendency So central tendency in a data set, which is the value which is coming at the center How the center values are? Representing so mean is the total average divided by n we take the total value divided by number of observation Medium is the middle value. We take the middle value Or if it is a even data set we take the average of middle two values And if it is mode we take the most frequent value Okay, if it is Highly which is whichever value is coming Highest or the most repeated value that is four we take four if it is like this we take two four and five If it is like this, there is no mode. Okay So let me tell you when we are taking mean and median on what occasion Mode we hardly take and you can't see any article any research where mode has been taken. It is just for the Exam purpose you can write a test mode That is one of the measure of central tendency