A company investigates the relationship between the distance d d\,d miles travelled by a delivery van and the fuel f f\,f litres used. For 16 journeys, the regression line of f f\,f on d d\,d is f=0.091d+1.8f=0.091d+1.8f=0.091d+1.8.
Interpret the gradient in context.
Estimate the fuel used for a journey of 120 miles.
Explain why the intercept should be interpreted cautiously.