\nIn this video, we’re going to look at frequency tables.These numbers are enough to give someone a headache and there's only 200 of them. `Lot's of datasets have thousands of even millions of pieces of data so, we need to collect and...\nIn this video, we’re going to look at frequency tables.These numbers are enough to give someone a headache and there's only 200 of them.
`Lot's of datasets have thousands of even millions of pieces of data so, we need to collect and record the data in tables to make it manageable. Thankfully, we can group this data into a nice neat table like this, which we can then easily put it into a bar chart.
Sometimes the data can be left as individual numbers and sometimes it's easier to group it, like I grouped the exam results.
So, we have these ages, we can collect into a frequency table by tallying: 16,19,20,22,19 and carrying on for all the data, then add your tally marks to get the frequency and we have a completed frequency table which is much easier to work from.
I could have just as easy chosen to group the numbers into categories for example. When creating 18 groups it's best to try and make the group the same size. So, let's go back to our exam results. These groups are different sized: this one is 10, these are 14 and this one is 30. Let's try to make it more quest. We know that the lowest mark was 22% and that the highest mark was 100%, so the range of results is 78% Now, because we have A* ,B,C,D and E; so, 6 groups. work out approximately how big each group should be by diving the range by 6. We want each group to be 13% in size, starting from the bottom at 22, add 13, so it's 35. So the next group starts at 35, adding 13 each time and then fill the rest of the group at the end.
We now have 6 groups that are pretty much the same class width. Here are some questions for you to do. Pause the video, work them out and click play when you're ready.
How did you get on? One final question for you to do: create four equal groups or classes for this data. Pause the video, work it out and click play when you're ready.
Did you get the groups right? That's the end of frequency tables. They’re very useful for collecting data together, to make it easier to handle. We can also calculate averages and create different graphs from them - like histograms, which we will look at in other videos.\n
![\"Frequency](\"https://static.lp.lexp.cloud/images/attachment_defaults/resource/large/missing.png\" "\\"Frequency")
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