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Visualizing Data in Statistics

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Hannah

09/12/2025

Maths

Representations of data

268

9 Dec 2025

2 pages

Visualizing Data in Statistics

user profile picture

Hannah

@hannah_studys1012

Statistics isn't just about numbers - it's about spotting patterns... Show more

Outliers
→ greater than Q3 + K(Q3-Q₁)
→ less than Q₁
K(Q3-Q₁)
The lengths, in cm, of 12 giant African land snails are given below:
17, 18, 1

Outliers, Box Plots, and Cumulative Frequency

Outliers are those weird data points that stick out like a sore thumb from the rest of your dataset. You can spot them using two methods: either they're more than 2 standard deviations away from the mean, or they fall outside the range of Q₁ - kQ3Q1Q₃ - Q₁ to Q₃ + kQ3Q1Q₃ - Q₁.

When working with the mean and standard deviation, remember that outliers are values greater than mean + 2σ or less than mean - 2σ. In the snail example, with a mean of 21cm and standard deviation of 3.83, any snail longer than 28.69cm or shorter than 13.34cm would be considered an outlier - making that 32cm snail definitely unusual!

Box plots give you a brilliant visual summary of your data's key features. They show you the quartiles (Q₁, median, Q₃), the range, and any outliers as separate points. The "box" contains the middle 50% of your data, whilst the "whiskers" extend to show the spread.

Top Tip: When drawing cumulative frequency graphs, always plot the cumulative frequency against the upper boundary of each class interval - this makes reading off percentiles much more accurate.

Cumulative frequency helps you find medians, quartiles, and percentiles quickly. Simply read across from the relevant position like60forthemedianwhenn=120like 60 for the median when n=120 to find these key values on your graph.

Outliers
→ greater than Q3 + K(Q3-Q₁)
→ less than Q₁
K(Q3-Q₁)
The lengths, in cm, of 12 giant African land snails are given below:
17, 18, 1

Histograms and Comparing Data

Histograms might look like bar charts, but they're completely different beasts. The key rule is that area equals frequency, not height. This means you need to calculate frequency density by dividing frequency by class width before drawing anything.

Different class widths make histograms tricky - a class that's twice as wide needs half the height to represent the same frequency. Always create a frequency density table first, showing class width and frequency density calculations. This stops you making costly mistakes in exams.

When you need to interpolate (split up bars), assume the data is evenly distributed within each class. It's not always perfectly accurate in real life, but it's the best assumption you can make with grouped data.

Exam Strategy: For comparing data questions, always mention both location (central tendency) and spread. Use mean and standard deviation for normal data, or median and IQR when you've got outliers or skewed distributions.

Comparing datasets requires you to comment on both where the data sits (location) and how spread out it is. Don't just say "Dataset A is higher" - explain whether it's the mean or median that's higher, and discuss whether one dataset is more variable than the other.



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Anna

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Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

 

Maths

268

9 Dec 2025

2 pages

Visualizing Data in Statistics

user profile picture

Hannah

@hannah_studys1012

Statistics isn't just about numbers - it's about spotting patterns and making sense of data all around you. From identifying unusual measurements in scientific studies to comparing different groups of data, these skills help you become a critical thinker who... Show more

Outliers
→ greater than Q3 + K(Q3-Q₁)
→ less than Q₁
K(Q3-Q₁)
The lengths, in cm, of 12 giant African land snails are given below:
17, 18, 1

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Outliers, Box Plots, and Cumulative Frequency

Outliers are those weird data points that stick out like a sore thumb from the rest of your dataset. You can spot them using two methods: either they're more than 2 standard deviations away from the mean, or they fall outside the range of Q₁ - kQ3Q1Q₃ - Q₁ to Q₃ + kQ3Q1Q₃ - Q₁.

When working with the mean and standard deviation, remember that outliers are values greater than mean + 2σ or less than mean - 2σ. In the snail example, with a mean of 21cm and standard deviation of 3.83, any snail longer than 28.69cm or shorter than 13.34cm would be considered an outlier - making that 32cm snail definitely unusual!

Box plots give you a brilliant visual summary of your data's key features. They show you the quartiles (Q₁, median, Q₃), the range, and any outliers as separate points. The "box" contains the middle 50% of your data, whilst the "whiskers" extend to show the spread.

Top Tip: When drawing cumulative frequency graphs, always plot the cumulative frequency against the upper boundary of each class interval - this makes reading off percentiles much more accurate.

Cumulative frequency helps you find medians, quartiles, and percentiles quickly. Simply read across from the relevant position like60forthemedianwhenn=120like 60 for the median when n=120 to find these key values on your graph.

Outliers
→ greater than Q3 + K(Q3-Q₁)
→ less than Q₁
K(Q3-Q₁)
The lengths, in cm, of 12 giant African land snails are given below:
17, 18, 1

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Histograms and Comparing Data

Histograms might look like bar charts, but they're completely different beasts. The key rule is that area equals frequency, not height. This means you need to calculate frequency density by dividing frequency by class width before drawing anything.

Different class widths make histograms tricky - a class that's twice as wide needs half the height to represent the same frequency. Always create a frequency density table first, showing class width and frequency density calculations. This stops you making costly mistakes in exams.

When you need to interpolate (split up bars), assume the data is evenly distributed within each class. It's not always perfectly accurate in real life, but it's the best assumption you can make with grouped data.

Exam Strategy: For comparing data questions, always mention both location (central tendency) and spread. Use mean and standard deviation for normal data, or median and IQR when you've got outliers or skewed distributions.

Comparing datasets requires you to comment on both where the data sits (location) and how spread out it is. Don't just say "Dataset A is higher" - explain whether it's the mean or median that's higher, and discuss whether one dataset is more variable than the other.

We thought you’d never ask...

What is the Knowunity AI companion?

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

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Most popular content in Maths

Most popular content

English - inspector calls quotes and analysis

Quotes from every main character

English LiteratureEnglish Literature
10

Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.9/5

App Store

4.8/5

Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user