Tony is investigating the relationship between his daily energy bill in pounds (eee) and the average daily temperature in degrees (ttt) each day in the winter.
He finds that the equation of the regression line is e=7.3−0.4te = 7.3 - 0.4te=7.3−0.4t
Describe the correlation between Tony's bill and the average daily temperature.
Give an interpretation of the gradient of this regression line.
Explain why this model might not be appropriate for Tony's energy bill in the summer.
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.