Final answer:
To test the hypothesis about car sales by engine type in England in 2015, secondary data is most suited as it involves analyzing pre-existing records, saving time and resources.
Step-by-step explanation:
The hypothesis in question refers to the number of cars with petrol engines sold compared to those with diesel engines in England in 2015. To investigate this hypothesis, the most suited type of data would be secondary data. Secondary data includes information collected by someone else that is relevant to the current research question. In this case, records of car sales by fuel type for the year 2015 would already exist, compiled by various agencies such as the automotive industry, government transport departments, or market research firms.
Using secondary data is beneficial as it saves time and resources. It involves analyzing pre-collected information that can answer the research question without the need for new, costly, or time-consuming primary data collection. Therefore, secondary data is the best choice for testing the stated hypothesis about car sales in England in 2015.