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Further Maths Textbook (Index) Statistics (Basic Terms) Study Notes Variables: If you collect data of height, weight or hair colour in class. These data are different depending on students, therefore these terms (categories) are called variables. Data Numerical Data: data described by numbers Discrete data: data has only particular numbers, Yr11 or 12, footy scores, number of people Continuous data: data can be any detailed value: Height (175.3cm), weight, distance, Categorical Data: colours, seasons, sex (male, female), nationalities Histograms and Bar charts Histogram and bar chart are similar. Each bar chart is separated unlike histogram. Generally speaking data of histograms are used for continuous numerical data, whereas bar charts include discrete numerical or categorical data. Mean (average) The sum of all the value / the number of data Eg. The mean of 10, 11, 15 is (10 + 11 + 15)/3 = 12 Median The central value Eg. The median of 2, 2, 4, 5, 7 is 4. (4 is the third value from the bottom as well as the top) Mode The value whose frequency is the largest Eg. The mode of 2, 3, 3, 4, 5, 5, 6, 6, 6, 7 is 6. IQR with Q1, Q2 and Q3 Q2 is the median of the data, Q1 is like the median of former half of the data, between the lowest datum and Q2. Q3 is like the median of Q2 and the largest datum. IQR = Q3 – Q1, half of the data belong to the IQR. Eg. In the raw data “4, 5, 5, 6, 7, 9, 10”
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