Regression and correlation
Regression and linear correlation for IB Analysis and Approaches HL: scatter diagrams, Pearson's r, regression lines and predictions, with IB questions.
When you know two data values for each individual (height and weight, hours of study and mark), statistics helps you see whether they are related. In this topic you represent the data on a scatter diagram, measure the strength of the linear relationship with the correlation coefficient , and obtain the regression line to make predictions, knowing when they are reliable. In the exam almost everything is done on the graphic display calculator (Paper 2), but you must interpret the gradient, the value of and the predictions in the context of the problem.
Recommended order
Follow the sections in order: bivariate distributions, linear correlation and regression line. At the end you will find IB exam questions grouped by type.
Descriptive statistics (topic 12) and the equation of a straight line.
Sections in this topic
Bivariate distributions and scatter diagrams
Paired data (x, y), scatter diagrams, the mean point and standard deviations of each variable, using the GDC. IB Analysis and Approaches HL.
3 worked examples Section 2Linear correlation and Pearson's r coefficient
Types of correlation, Pearson's r and covariance: interpretation, GDC calculation and why correlation is not causation. IB Analysis and Approaches HL.
3 worked examples Section 3Regression line and predictions
Regression line of y on x: finding it with the GDC, interpreting gradient and intercept, and when predictions are reliable. IB Analysis and Approaches HL.
3 worked examples End of topicIB exam questions: topic 13
IB exam questions on regression and correlation: scatter diagrams, the r coefficient, the regression line and predictions, with step-by-step solutions.
21 exercises · 6 ★★★ levelStuck on this topic?
Tell us where you get lost and we will tell you how to tackle it. Álvaro replies on WhatsApp.
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