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A second hand car dealer has ten cars for sale. He decides to investigate the link between the

ages of the cars, *x *years and the mileage, *y *thousand miles. The data collected from the cars

are shown in the table below.

Age, *x *years

2 2.5 3 4 4.5 4.5 5 3 6 6.5

Mileage, *y *thousand miles

22 34 33 37 40 45 49 30 58 58

(a) Construct a well labeled **scatter **diagram in the graph paper provided to present the

information. (3 marks)

(b) Find *S**xx *and *S**xy*. (3 marks)

(c) Find the regression equation in the form *y *= *α *+ *βx*. (4 marks)

(d) Fit the regression equation obtained in (c) to the scatter plot in (a) and label the line

appropriately. (2 marks)

(e) Give a practical interpretation of the slope *β*. (1 mark)

(f) Using your answer in (c), fifind the mileage for a 6 year old car.

A second hand car dealer has ten cars for sale. He decides to investigate the link between the

ages of the cars, *x *years and the mileage, *y *thousand miles. The data collected from the cars

are shown in the table below.

Age, *x *years

2 2.5 3 4 4.5 4.5 5 3 6 6.5

Mileage, *y *thousand miles

22 34 33 37 40 45 49 30 58 58

(a) Construct a well labeled **scatter **diagram in the graph paper provided to present the

information. (3 marks)

(b) Find *S**xx *and *S**xy*. (3 marks)

(c) Find the regression equation in the form *y *= *α *+ *βx*. (4 marks)

(d) Fit the regression equation obtained in (c) to the scatter plot in (a) and label the line

appropriately. (2 marks)

(e) Give a practical interpretation of the slope *β*. (1 mark)

(f) Using your answer in (c), fifind the mileage for a 6 year old car.

A second hand car dealer has ten cars for sale. He decides to investigate the link between the

ages of the cars, *x *years and the mileage, *y *thousand miles. The data collected from the cars

are shown in the table below.

Age, *x *years

2 2.5 3 4 4.5 4.5 5 3 6 6.5

Mileage, *y *thousand miles

22 34 33 37 40 45 49 30 58 58

(a) Construct a well labeled **scatter **diagram in the graph paper provided to present the

information. (3 marks)

(b) Find *S**xx *and *S**xy*. (3 marks)

(c) Find the regression equation in the form *y *= *α *+ *βx*. (4 marks)

(d) Fit the regression equation obtained in (c) to the scatter plot in (a) and label the line

appropriately. (2 marks)

(e) Give a practical interpretation of the slope *β*. (1 mark)

(f) Using your answer in (c), fifind the mileage for a 6 year old car