GCSE Statistics study guide
GCSE Statistics · Work through your exam, one topic at a time.
GCSE Statistics (8382) is a UK general qualification offered by AQA, one of the awarding bodies that sets GCSE and A-level examinations in England. It is designed for students who want to build a working understanding of how data is gathered, organised, presented and interpreted, rather than for those seeking a purely mathematical route. The GCSE Statistics study guide has 6 sections and about 1,780 words.
01Populations, samples and data collection
A population is every item that could be studied; a sample is a subset chosen to represent it. A census measures the whole population - accurate but slow and expensive - while a sample is cheaper but introduces sampling error.
333 words, about 2 min02Processing, representing and analysing data
Raw data must be organised before it can be interpreted. Frequency tables record counts; grouped frequency tables put continuous data into class intervals, and the midpoint of each class is used later for estimates.
292 words, about 1 min03Summarising data: averages and spread
There are three averages. The mean = sum ÷ count and uses every value; the median is the middle value once data are ordered, at position (n + 1)/2; the mode (or modal class for grouped data) is the most common value.
292 words, about 1 min04Scatter diagrams and correlation
A scatter diagram shows paired bivariate data, one variable on each axis. Put the explanatory (independent) variable on the x-axis and the response (dependent) variable on the y-axis.
283 words, about 1 min05Time series and moving averages
A time series is a set of values recorded at regular intervals. Its components are the trend (long-term direction), seasonal variation (a pattern repeating within a fixed period, such as a year), and random or irregular variation.
291 words, about 1 min06Probability
Probability is measured on a scale from 0 to 1. For equally likely outcomes, P(event) = favourable outcomes ÷ total outcomes, and P(not A) = 1 − P(A).
289 words, about 1 min