Statistical Investigation on Car Prices

Statistical Investigation on Car Prices

Data Collection: We are asked to find the relationship between prices

of ‘51 registered’ cars and variables such as their current new

price, mileage and weight by using the regression analysis. To collect

full information of these registered cars, we can access to the

websites like: http://www.exchangeandmart.co.ukHowever, in this easy,

we use the data, which are provided with the assignment by our

teachers.

By the sources, 100 cars, which manufacturers include Toyota, Honda,

Nissan, Suzuki, are obtained to be sampled from. These Japanese cars

can be divided into three groups according to different engine size,

which are small engine size, medium engine size and large engine size.

The carsÂ’ engines size under or equal to 1.5 liters are considered as

small engine cars. Group of medium engine cars are the carsÂ’ engine

size between 1.6 to 2.4 liters. Large engine cars are carsÂ’ engine

size equal or bigger than 2.5 liters.

The samples are likely to be representative because the method of

simple random sampling will be used. The data of cars is wide range,

so we use calculation to choose the samples randomly. The processes of

sampling are divided into three procedures. Firstly, order all the

cars by number them from 1,2,3 until 100. Secondly, decide the number

of samples and calculate how many samples should be chose from each

group. In this case, I decide to select 30 samples. Finally, use the

calculation to randomly choose certain samples from a variety of data.

In calculation, press “mode” and then chose fix. After that use the

number of cars to be chose from multiple Ran# and add 1, which will

give you the representative samples selected by calculation.

The numbers of the cars we choose from each group are calculated as

showed below:

32/100 ´30 = 10, so 10 data should be chose from group of small

engine cars .

61/100´30 = 18, so 18 cars out of 100 cars of medium engine cars will