Descriptive Statistics & Probability

University 7 questions

What descriptive statistics & probability means

This skill helps you describe data with averages and spread, then use simple chance ideas to answer short questions. It matters because you need it for clear data interpretation in later statistics work and many entry tests.

What you will practise

Find the mean from a small set of numbers.
Identify the median after ordering the data.
Choose the correct spread measure for a data set.
Use basic probability language for simple events.

Before you start

You should be comfortable with arithmetic, ordering numbers, and reading simple tables or lists. You also need to know fractions and decimals at a basic level.

Worked example

One question from this skill's own question bank, shown with its full working.

Question

The mean of the data set 2, 4, 6, 8 is

Answer: 5

Working: Mean = (2 + 4 + 6 + 8) / 4 = 20 / 4 = 5.

Common mistakes to avoid

Adding values correctly but forgetting to divide by the number of items for the mean.
Taking the middle value without first arranging the data in order.
Mixing up standard deviation with range or variance in spread questions.
Treating every simple chance statement as certain instead of using probability rules.

Curriculum and exam alignment

Tertiary foundation coursework

In university and tertiary foundation programmes, this topic usually appears early in introductory statistics work and general maths support. It links directly to later coursework and professional entrance tests that ask for data summaries and basic probability.

Curriculum notes are a general guide to where this work normally sits. Always check the syllabus your school or examination body is currently using.