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00:00Hi kids! In the last lesson we learned what is average and the two types of average, mean and mode.
00:10Today we will learn the other type of average, the median and range. So let's get started.
00:20We learned there are four types of averages, mean, mode, median and range.
00:28The mean is what you get if you share everything equally.
00:33The mode is the most common value.
00:36And median is the value in the middle of an ordered set of data.
00:43Here is a list of numbers and we will learn finding the other two types of averages, that is, the median and range.
00:54Let's find median for this list of numbers.
00:58Median is the middle value in a list of ordered numbers.
01:04Let's learn how to find the median in a list of numbers.
01:09To find the median, your numbers have to be listed in increasing order.
01:15If there are odd numbers of numbers, then middle number is the median.
01:21And if even number of numbers are there, then mean of two middle numbers is the median.
01:29Let's learn more with the help of an example.
01:33Let's find the median of the list.
01:37First arrange the numbers in order, either increasing order or decreasing order.
01:44Circle the number at each end of the list.
01:48Keep circling numbers two at a time, one from each end, until you have only one or two uncircled numbers in the center.
02:00Doing like this.
02:03We are left with one number, that is, 13.
02:07So 13 is the median of this list.
02:13Let's take another example.
02:16Let's find the median of the list.
02:20First arrange numbers in order, either increasing order or decreasing order.
02:26Now here we have the ordered list.
02:30Now circle the number at each end of the list.
02:34And keep circling numbers two at a time, one from each end, until you have only one or two uncircled numbers.
02:45And here we are left with two numbers in center, 13 and 16.
02:53If we cut them, we will not be left with any number.
02:58Then how do we find its median?
03:02In such cases, where even number of numbers are there in the list, we are always left with two middle numbers.
03:11And the mean of those two middle numbers is the median of the list.
03:17So, in order to find the mean of the middle two numbers, add 13 and 16, then divide by 2.
03:2813 plus 16 equals 29.
03:33And 29 divided by 2 is 14.5.
03:40So, 14.5 is the median of the list.
03:46Now, let's see what is range.
03:50It is the difference between the largest and smallest number in the list of numbers.
03:56Let's find the range of this list of numbers.
04:00Biggest number in the list is 34.
04:05And smallest number in the list is 7.
04:09So, 34 minus 7 equals 27.
04:15So, 27 is the range of the list.
04:20Let's practice a few examples to find out the median and range.
04:27The weekly salaries of five employees are $300, $400, $350, $600, and $150.
04:42For these five salaries, find the median and range.
04:47Let's first find median.
04:51In order to find median, we need to arrange salaries in an order.
04:56It can be increasing or decreasing order.
05:00Now, cross two figures, one from left and one from right at the same time.
05:08Repeat the same.
05:10Until you are left with only one or two numbers in the center.
05:16So, cutting one more number from each side, we are left with only one number.
05:22And this one number left in the middle of the list is median.
05:28So, $350 is the median.
05:33Now, let's find the range.
05:37In order to find the range, we subtract the smallest value of the list from the biggest value.
05:45The biggest value is $600, and the smallest value is $150.
05:53Subtracting $150 from $600, we get $450.
06:01So, $450 is the range.
06:06Now, let's take another example.
06:10The test scores of 10 students are 67, 78, 90, 60, 56, 89, 95, 45, 34, and 89.
06:26For these scores, we have to find the median and range.
06:32Let's first find median.
06:36We know in order to find the median, we arrange the numbers in an order.
06:42So, we have arranged the numbers in an order.
06:46Now, cross two figures, one from left and one from right at the same time.
06:53And keep doing that until you are left with only one or two numbers in the center.
07:01Now, we are left with two numbers in the center.
07:06And when we are left with two numbers in the center, we find the mean of those two numbers to get the median.
07:15So, let's find the mean of middle two numbers.
07:20We know we, for find the mean of two numbers, we add the numbers and divide by two.
07:28So, add 67 and 78 and divide by two.
07:3567 plus 78 equals 145.
07:41145 divided by two equals 72.5.
07:48So, 72.5 is the median range.
07:56Now, let's find the range.
07:59The biggest score is 95 and the smallest value is 34.
08:05And the range is the difference between the biggest and the smallest value.
08:1195 minus 34 is 61.
08:16So, 61 is the range.
08:20So, kids, today we learned how to find the median and range of a given list of numeric figures.
08:28Now, you may go ahead and take a quiz to learn more.
08:32Bye-bye.