A regression line for predicting delivery time y y\,y minutes from distance x x\,x km is y=1.8x+12y=1.8x+12y=1.8x+12, fitted for distances from 2 km to 20 km.
Estimate the delivery time for a journey of 15 km.
Explain why rearranging this line to estimate distance from an observed delivery time is not generally valid.
State whether predicting at 25 km is interpolation or extrapolation.
121 exam-style questions on OCR (MEI) A Level Maths 2.2 Data Presentation and Interpretation, covering 2.2.1 Types of data and standard diagrams, 2.2.2 Area in a histogram is proportional to frequency, 2.2.3 Cumulative frequency diagram, 2.2.4 Describe frequency distributions, 2.2.5 Samples and theoretical distributions, 2.2.6 Interpret a scatter diagram, 2.2.7 Distinct sections and outliers in scatter diagrams, 2.2.8 Correlation and causation, 2.2.9 Select or critique data presentation techniques, 2.2.10 Measures of central tendency, 2.2.11 Simple measures of spread, 2.2.12 Variance and standard deviation, 2.2.13 Outliers, 2.2.14 Cleaning data, and 2.2 Data Presentation and Interpretation. Each one has a worked solution and a mark scheme showing where the marks go.