As part of my GCSE Statistics coursework investigation, I have been asked to investigate the factors, which affect the price of a car. To do this I have to break the investigation down into smaller questions. From my point of view the following information that we have been given, has very little or no affect on the price of the car, therefore they will not be investigated:

- Insurance
- Doors
- Central locking
- Seats
- Gearbox
- Airbags

The question I have chosen, “What factors affect the price of a used car?” now needs to be broken down into sub-questions to find out which factors affect the price of a car the most. The sub-questions are as follows:

- How do the make, model and age of a car affect its price?
- How does the colour of the car affect the value of the car?
- If the car has been serviced, what affect does this have on the price of the car?
- How does a cars mileage affect its price?
- Does the number of owners affect the car value?
- Does the length of a car’s MOT affect its value?
- If a car has air conditioning, then does its value rise?

For this investigation I am going to take a sample size of 60 cars from which I will try and take at least 2 of each car, so that I am able to compare two of the same types of car. However, the sample will not be random if I choose the cars myself. Therefore, to make sure that the sample I choose to use is fair, I will place each number into a hat and pick out 60 numbers. The 60 numbers I pick out will be used for my investigation.