GCSE Math's Statistics Coursework Introduction: I have been given a database which contains information about one hundred different used cars

This graph shows that I have compared price to age. I am not too happy with this graph due to the trendline appears to have been drawn wrong by the outliers. I will now remove the outliers so that I can get a more accurate trendline on excel.

Now that I have removed the outliers from the original graph and I have also added the equation for the graph which shows me that for the cars that I have they will lose £854.76 every year on average.

This graph shows that I have compared comparing price and mileage.  I am not too happy with this graph due to the trendline appears to have been drawn wrong by the outliers Bentley Rolls Royce. I will now remove the outliers because they are skewing my data to make the trendline inaccurate, I will also add the formula of the graph on to the trendline.

I have now changed my graph by removing the 5 outliers that were skewing my data, Now that I have removed the outliers from the original graph and I have also added the equation, which shows me that for every mile a car has done it has lost almost 5.01pence. This is the percentage of depreciation of the cars.

Now that I have done the price against age and mileage for all the cars, I will now compare those using specific makes of cars such as Ford and Vauxhall. Firstly I will do Fords, as they are the most numerous of all the cars in the table. Then I will compare my results.

I have now made a Ford graph for price against mileage, and the equation on the trendline shows me that for every mile a Ford car has done it will lose on average more or less 9 pence which I have rounded. I will now use the Ford data to compare price to age.

This is the graph that made with the data given to me when I compared price to age on Ford cars. The equation which I have put on the trendline tells me that every year on average the price will reduce by £808.77.I  find the graph not acceptable because the cars will loss the largest percentage of their value in the first year on the road and the amount of depreciation will reduce every year at a steady rate.

These two graphs which I have done on Ford shows me, that for every one unit of measurement of the cars age the more influential to the price of the car. However the car might do far more miles than it will age for example a Ford car may do 10,000 miles in one year so it will loss on average £89.9.

The age of the car is still more influential but on the first year it will use most of its value in the first year and the depreciation will decrease every year at a steady rate.

 

I will now compare Vauxhall to Fords but first I have to do the price for Vauxhalls.

I have now done the graph and the price depreciation is exactly £772.96 compared to the Ford car depreciation it is £808.77 which shows that the Vauxhalls loss less money every year.

This is the Vauxhalls price/mileage and for every mile a car does it will loses 0.082 pence compared to the Fords 0.089 pence which shows that there is a minute difference between the two different car makes but not enough to be influenced.

When I compared the Vauxhalls to the Fords I found that the Vauxhalls depreciate less than the Fords over the years.

I will now make some graphs for the price depreciation against the age and also against the mileage for all the vehicles and then for the Fords and Vauxhalls.

The trendline which I have made by excel shows that this is a very strong positive

correlation and also the equation shows me that in the first year of the car will depreciate about 50% on average and in the second year it will depreciate by 60% and in the third year a car will depreciate by a little over 60%. I have found out this information by reading of my graph, so the car will loose most of its value in the first year and then it will depreciate on a steady rate.

   

This graph which I have made shows me that there is again a very strong positive correlation as the points are very close together, also the cars will depreciate 0.0006% on average for every mile it has done. I have found this out by looking at my graph that I have made.

Conclusion

From all the information that I have made from my coursework I have come to the conclusion that there are many things that affect the price of a second hand car these include:

• Style
• Central locking
• Seats
• Gearbox
• Air conditioning
• Airbags
• MPG
• Mileage
• Service
• Owners
• Length of MOT
• Tax
• Insurance group
• Doors
• Age
• Colour
• Engine
• Fuel

And many more.  I have got all these suggestions from my excel table which my coursework has been based upon. There are also some exceptions which influences the price of the car; the cars that are the exception (outliers) gains money due to that these are vintage cars e.g. Bentley, Mercedes and many others. This will nearly always be the case because there will always be cars that gain with mileage and those that will lose money with mileage. The data which I have collected has proven quite true in my hypothesis and my plan.