Summarizing Data: Mean, Median, Mode2:35 with Ben Deitch
There's more than one way to talk about the 'middle' of a dataset. In this video we'll look at mean, median, and mode and see when you might want to use each one!
Now that we've got some bounds for 0:00 our data, it would be nice to know where the middle is. 0:01 Unfortunately, there is a few different ways to define the middle. 0:05 Let's look at three of them. 0:08 The first and most common way to look at the middle of a data set 0:10 is to use the mean, also known as the average. 0:13 To find the average of a set, add up all the values and 0:16 then divide by how many values there are. 0:20 One problem with averages is that they're easily influenced by outliers. 0:22 If we're looking at these eight bowling scores, 0:27 the average is higher than every value but the highest. 0:29 In this case, instead of using the average to find the middle, 0:33 it might be better to use the median. 0:36 The median represents the middle value in a data set. 0:39 If your data set has an even number of values and thus no true middle value, 0:42 then the median is the average of the two middle values. 0:48 So for our bowling data set, the median value would be 115, which 0:51 does a much better job of representing the middle than the average did. 0:56 The last way we can try and find the middle is to use the mode. 1:00 The mode is them most frequent value in our data set. 1:04 In our bowling data set, there's only one repeated value, so our mode has to be 90. 1:07 Back in the spreadsheet, let's calculate these values for our data set. 1:12 Let's add the labels starting at A5, average, 1:17 median and mode. 1:21 And then let's highlight those labels and hit command or ctrl B to make them bold. 1:26 Then in column B let's use functions to figure out these values. 1:31 In B5, let's type =AVERAGE. 1:35 Hit Enter to select it, paste in our range, hit Enter again and there we go. 1:40 Now let's do the same thing for the median and mode. 1:47 Type in the function, 1:51 paste in the range, and hit Enter. 1:56 And there we go, except for the mode, 2:03 looks like it's not using the right data type. 2:06 So let's click this button up here, and 2:10 instead of Automatic let's set it to Duration. 2:12 There we go. 2:18 All right, not only do we have information about the edges of our data but 2:19 now we have a pretty good idea of where the middle is. 2:24 If you'd like to learn more about mean, median and 2:27 mode, check out the teacher's notes. 2:29 Coming up, we'll look at a few ways to figure out the spread of our data. 2:31
You need to sign up for Treehouse in order to download course files.Sign up