# 4.9 Normal Distribution

## Normal?

The normal distribution is a fascinating, naturally occurring phenomenon that has very relevant applications to understanding the world around us. When a data set is normally distributed it has some key properties that allow us to make predictions about the nature of the data set. The videos below go in to detail about those properties and how to use them to solve problems.

Key Concepts

In this unit you should learn to…

• Understand the nature and properties of data that is normally distributed

• Calculate probabilities using the symmetrical properties of the normal distribution

• Calculate probabilities using your GDC

• Understand and use the inverse normal function

Essentials

Slides Gallery

Use these slides to review the material and key points covered in the videos.

1. What is the normal distribution?

This video intoduces the idea of data sets and distributions leading to the key properties.

2. The symmetry and structure of the Normal Distribution

Here we look at the fundamental symmetrical properties and how we use them to solve problems.

3.The Normal CDF function.

This video goes through using your GDC and the Normal CDF function to solve problems

4. The Inverse Normal function.

This video goes through using your GDC and the Inverse Normal function to solve problems

Summary

Review these condensed 'key point' revision cards to help you check and keep ideas fresh in your mind.

Test yourself

#### Self checking quiz

Practice your understanding on these quiz questions. Check your answers when you are done and read the hints where you got stuck. If you find there are still some gaps in your understanding then go back to the videos and slides above.

Exam Style Questions

The following questions are based on IB exam style questions from past exams. You should print these off (from the document at the top) and try to do these questions under exam conditions. Then you can check your work with the video solution.

Question 1 Video solution

Question 2 Video solution

Question 3 Video solution