# 4. Statistics & Probability

The **Statistics & Probability topic** is the syllabus topic (out of 5) that has the least amount of HL content. The *suggested teaching hours* for **SL** is **27 hours** and it's only a few hours more for **HL** at **33 hours**. The additional content for HL consists of Bayes' theorem and further material on discrete & contrinuous random variables. Discrete probability distributions (including binomial) and the normal distribution (a continuous distribution) are included in the SL core syllabus content.

**∼ quick link ∼**__downloadable tests & quizzes__ for teaching units in **Stats & Probability **

**Changes compared to previous Maths HL-SL syllabusses**:

Previously, **linear correlation of bivariate data** was in Maths SL, but __not__ Maths HL. WIth linear correlation/regression in the SL content - and with Analysis SL a subset of Analysis HL - both SL and HL students need to cover it. Other changes include the addition of the following syllabus items:**SL 4.1*** reliability of data sources and bias in sampling; sampling techniques: simple random, convenience, systematic, quota and stratified methods**SL 4.2*** determining whether data may be normally distributed by symmetry of a box and whiskers plot**SL 4.10 **equation of regression line of *x *on *y*; use equation for prediction purposes and know when it’s reliable

Another change is that the **Poisson distribution** has been removed; it's not in SL or HL.

**Statistics & Probability - syllabus overview**

Syllabus item numbers are in brackets.

__SL - Stats & Probability__

**SL core (AA & AI)**

data sampling & populations (4.1)

descriptive statistics (4.2, 4.3)

linear regression (4.4)

probability of events (4.5, 4.6)

probability distributions (4.7, 4.8, 4.9)

**SL (AA)**

linear regression (4.10)

further conditional probability (4.11)

normal distribution extended (4.12)

__HL - Stats & Probability__

**HL (AA)**

Bayes’ theorem (4.13)

discrete & continuous random variables (4.14)

### Exercise Sets, Quizzes & Tests

AA_Quiz1_probability_v1

Quiz on 'probabilities of events' that is suitable for both SL and HL students. Quiz has 7 questions and GDC is allowed on all. Solution key (**worked solutions**) available below.

AA_Quiz1_probability_v1_SOL_KEY

Solution key (**worked solutions**) for above SL-HL quiz on 'probabilities of events'.

AA_HL_Test1_probability_v1 __syllabus content on test__: probability rules for: combined events, mutually exclusive events & independent events; conditional probability; discrete probability distributions; continuous probability distributions; expected value (mean), variance & standard deviation for discrete & continuous distributions; binomial distribution; normal distribution. **Worked solutions** below.

AA_HL_Test1_probability_v1_SOL_KEY **Worked solutions** for HL Probability Test above.

## Selected Pages

### Probability distributions (TN) 25 August 2021

go to teaching materialsSyllabus content (* SL content shared with Applications & Interpretation course)SL 4.7* Concept...

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### Linear regression (TN) 26 July 2021

A more precise title for this syllabus content would be linear correlation of bivariate data - or, alternatively, bivariate...

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### Probability of events (TN) 10 February 2021

■ downloadable teaching materials for probabilities of eventsThe syllabus content on the probabilities of events overlaps...

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### 4E. Probability introduction (SN) 13 July 2020

… It is remarkable that this science, which originated in the consideration of games of chance, should become the most...

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