This third edition of SIGMA MATHEMATICS is the first full-colour textbook for NCEA Level 3 Statistics and Modelling. It is organised into the seven Level 3 Statistics and Modelling Achievement Strands, and much new material has been added: Time series analysis has been upgraded to include seasonal adjustments, index number series, forecasting and non-linear time series; Extensive new sections have been added on two-way tables (contingency tables) in probability, and the conditional probability section has been upgraded to include this approach; In linear programming there is a new section on the 'moving line' approach; Scatterplots and correlation are included, with many questions on understanding and interpretation; Regression includes a full treatment of the coeficient of determination, R2, and goes as far as non-linear regression; Worked examples on the three main probability distributions (normal, binomial, Poisson) have been upgraded to reflect the use of technology; The mathematical modelling section has been extensively revised to include a focus on curve fitting.