Given that x x\,x years is the life expectancy n n\,n years after 1960, a linear model linking x x\,x with n n\,n is
x=15n+72 x = \frac{1}{5}n + 72 x=51n+72In 2020 the life expectancy in the UK was 82.6 years. Comment on the suitability of the model in light of this information
260 exam-style questions on Edexcel A Level Maths Straight Line Graphs, covering 5.1 y = mx + c, 5.2 Equations of Straight Lines, 5.3 Parallel and Perpendicular Lines, 5.4 Length and Area, and 5.5 Modelling with Straight Lines. Each one has a worked solution and a mark scheme showing where the marks go.