Question: The classified advertisement columns of a local paper contain details of 12 used cars of a particular make and model. The prices of these cars and numbers of miles they have travelled are:

Price (£000)

6.8 6.2 5.7 4.7 6.0 5.9 7.0 4.5 5.0 3.0 3.8 3.5

Mileage (000)

9 13 11 33 14 11 3 19 22 35 40 44

(a) Identify the independent variable (X).

(b) Present these data in the form of a scatter diagram.

(c) Find the least squares line of best fit and plot it on your scatter diagram.

(d) Predict the price of a car of this type that has travelled 25,000 miles.