Statistics – AQA GCSE Maths (8300)

Key Concepts

• Data types: qualitative and quantitative, discrete and continuous
• Data presentation: tables, charts, bar charts, pie charts, histograms, scatter graphs
• Measures of central tendency: mean, median, mode
• Measures of spread: range, interquartile range, variance, standard deviation
• Probability and relative frequency
• Correlation and causation
• Sampling methods: random, stratified, systematic, opportunity, quota

Definitions & Examples

• Qualitative Data: Non-numerical data, e.g., favourite colour.
• Quantitative Data: Numerical data, e.g., test scores.
• Discrete Data: Countable values, e.g., number of students in a class.
• Continuous Data: Can take any value within a range, e.g., height in cm.
• Mean: Sum of data ÷ number of items.
• Median: Middle value when data is ordered.
• Mode: Most frequent value.
• Range: Difference between highest and lowest value.

Methods

• Organise data into frequency tables
• Draw and interpret charts and graphs
• Calculate mean, median, mode, and range
• Use scatter graphs to identify correlation
• Choose appropriate sampling methods for data collection
• Identify anomalies and trends in data sets

Advantages & Disadvantages

• Advantages: Supports decision making, summarises large data sets, identifies trends and relationships.
• Disadvantages: Misleading if sample is biased, data can be misrepresented in graphs, does not prove causation.

Practice Questions

• Calculate the mean, median, mode, and range of: 4, 7, 7, 10, 12
• Draw a bar chart for the number of students in 5 classes: 20, 25, 18, 22, 30
• Draw a scatter graph for paired data and describe the correlation
• Identify the most suitable sampling method for a school survey
• Interpret a histogram showing frequency distribution of exam marks